W. H. Davenport Adams

Ah, bitter chill it was!

The owl, for all his feathers, was a-cold;

The hare limped trembling through the frozen grass,

And silent was the flock in woolly fold.

—Keats.

T The winter of 1867-68 will count among the severest recorded in meteorological annals. As early as the winter solstice the cold began to make itself felt. In a few days the centigrade thermometer sank to 12° below zero, through the influence of a very keen north-east wind. At Paris, where, on an average, the winter temperature is two degrees higher than in the surrounding country, the Seine was completely frozen for upwards of a fortnight. To meet with a similar phenomenon we must go back as far as 1788. In January 1830, when, on the 17th, the temperature sank down to 17°.3, the Seine was also frozen, but the ice speedily melted. The extreme cold of 1788 coincides, like that of 1830, with the appearance of two comets. In bringing together these and other similar facts, some writers are induced to believe themselves authorised in establishing theories which attribute a certain frigorific influence to the comets. But no such coincidence existed in the winter of 1867-68, nor in any other years signalised by the occurrence of excessive frost.

What are we to think of the supposed influence of the moon upon the weather?

This question, so constantly revived, is here not out of place. The exceptionally prolonged cold, during which the thermometer remained for three weeks below zero, the barometer oscillating between 76° and 76°·5, commenced on the 22d of December, three days before the new moon; now, it is on Christmas-day, at 48 min. past 11 p.m., that the moon is found in conjunction,—that is to say, has become completely invisible to us by passing between the earth and the sun. And the thaw, which terminated this period of frost, commenced on the 12th of the following January, just three days after the full moon; the exact moment of its opposition, when the moon reflected upon us the whole hemisphere of its borrowed lustre, took place on the 9th, at 2 min. past 11 in the evening. It is then in the neighbourhood of the syzygies (conjunction and opposition) of the moon that we must place the commencement and termination of the cold period to which we have been alluding.

We should not have thought of recalling these coincidences, if it had not occurred to us that some meteorologists, in accordance with the popular belief, have attributed to the syzygies a marked influence on the changes of the weather. Toaldo has deduced from half-a-century's observations, taken at Padua, this general fact, that the maximum of influence manifests itself at the syzygies, and somewhat more at the new than at the full moon; that the minimum coincides with the first and second quarter; that the action of the perigee (minima distance of the moon from the earth) is equal to that of the full moon; and that the action of the apogee (maxima distance of the moon from the earth) is double that of the quarters. Observe that the Italian meteorologist extended this influence to three days before and three days after a phase, for the moon's passage through the syzygies; while he restricted it to a day before and a day after, for the quadratures.

The work which Toaldo did for the climate of Padua, Pilgram had already executed for that of Vienna. But the result at which he arrived, after five-and-twenty years of observation (from 1763 to 1788), was the contrary to that of Toaldo: namely, that the new moon is the least active of all the phases in reference to changes of weather. What, then, are we to conclude? That the problem is one of extreme difficulty, and that there are probably several elements necessary to its solution, which at present escape us. Then, too, we ought to have a clear understanding of what is meant by "changes of weather;" we must eliminate all vagueness from the word, and not allow it to be governed by any preconceived theory.

The Snow.

Thick clouds ascend, in whose capacious womb

A vapoury deluge lies, to snow congealed.

Heavy they roll their fleecy world along,

And the sky saddens with the gathered storm.

Through the hushed air the whitening shower descends;

At first thin wavering; till at last the flakes

Fall broad, and wide, and fast, dimming the day

With a continual flow.

—Thomson, The Seasons.

The earth is covered with snow; it is enveloped, as the poets say, in a shroud of white. But this phrase, poetical as it may appear, is, in reality, inadmissible. A shroud is used to wrap round a dead body, a corpse, whose elements, since they are no longer maintained united by the undefinable principle of life, go to form other compounds,—more permanent and lasting,—which will mingle with the earth, the water, and the air. But the earth which the snow covers preserves, on the contrary, the germ of life in the seeds and roots of plants; it rests itself, only for the purpose of communicating, at the return of spring, a new impulse to the sap, whose circulation sleeps during winter.

The moment is propitious for studying the snow: come, then, let us examine it.

And, first, what is snow? Put a little into the hollow of your hand, and see what transpires.

It melts, and leaves nothing but water as a residuum.

Snow, then, is frozen water,—water which existed in the atmosphere in the state of vapour, and which, to speak the language of physicists, has passed from the gaseous state into the liquid, and thence into the solid. If you doubt its identity with water, let a chemist analyse a portion of it for you: he will tell you that it is composed, like distilled water, of hydrogen and oxygen, in the proportion of two parts of the former to one part of the latter. The reader will, of course, understand that we abstract all foreign substances which may accidentally have got mixed up with it.

Fig. 5.—A Snowy Landscape.

It was once a wide-spread opinion that snow is favourable to vegetation, on account of the salts which it contains. Analysis, however, gave a negative result; it demonstrated the absence of these salts. Recourse was then had to another hypothesis: it was supposed that the air contained in snow is richer in oxygen than the free air, and that to the action of this gas must be attributed its fertilising property. Another error! The truth really is, that snow maintains the soil which it covers at a perceptibly constant temperature, and that, when thawing, it mellows it by its aqueous infiltrations; so that if, before a fall of snow, the earth has experienced the action of a strong frost capable of killing injurious insects, all the chances will be in favour of a fertile year.

Snow forms crystals. To observe them clearly, you must examine the snow which falls in very cold and dry weather. It then appears to be a dust composed of little thin plates. Look at the small flake which has fallen on your coat-sleeve; it is isolated; hasten to examine it before it melts, or before other flakes become amalgamated with it. What a graceful star! (Fig. 6, a). It is formed of six regular rays. There are others which have only three, four, or five rays. But on inspecting these more closely, you see that many of these rays are broken or abortive, and that, when finally analysed, each star possesses the same number of rays.

Why are there continually six rays? Why are there never more nor fewer than this number? One might suspect in nature a peculiar affection for the number six; as, for example, in the cells of the bees and the wasps, which form a regular hexagon (Fig. 6, b). Why, in the infinity of polygons, has the instinct of these insects only chosen one hexagon? What is the reason for this preference?

Fig. 6.

If you interrogate geometry, it will reply to you that, of all the polygons inscribed in a circle (Fig. 6, c), there is but one whose sides are equal to the radius of that circle; and this polygon is exactly that of the bee and wasp's cell. Here, then, is a very singular coincidence. If you afterwards examine very minutely the work of the bee, you will find in each cell of the honeycomb a pyramidal base, composed of three equal rhombs, whose angles solve a grand geometrical problem, that of giving the maximum of space with the minimum of matter. The papier-machÉ combs of the wasp are formed of a single row of cells, each of which has a nearly level bottom. This is all that is required; for these cells are destined, not for the reception of honey, but only of the larvÆ, the offspring of their architects.

Do not think that you have but to pick up a thumbful of snow to procure your crystals! These change their form very quickly, and it is almost impossible to detect it in snow which has remained for any length of time upon the ground. The great flakes which fall in relatively mild weather, when the temperature borders upon freezing-point, are often nothing better than masses of small amorphous atoms of ice; to get at the crystals, you must remove the kind of icy varnish which encases them.

For the accurate observation of the crystallisation of water which precipitates itself in the air, we have at our disposal a means as simple as convenient—a pane of glass. All we have to do is to arrange everything in such a manner that the congelation shall be both slow and certain; on this condition alone can we obtain well-defined crystals. A cold room is best adapted for this kind of experimentation; and thus you will frequently see deposited upon the window-glass, in an uninhabited chamber, some exceedingly graceful designs, as follow.

Fig. 7.

These are asteriÆ,—arborescent, and leaf-like crystals,—imitating the beautiful foliage of ferns and mosses. The severer the cold, the more regular, be it understood, is the formation of these crystals.

Owing to its dazzling whiteness, snow is a great reflector of light, and singularly illuminates the darkness of the winter nights. The long dreary nights of the polar world are lit up by the glories of the magnetic auroras, joined to the radiancy of the snow. This induces us to repeat a question which we have often addressed to ourselves, namely,—under what aspect must the very varied changes which the solar light experiences on the surface of our planet be presented to the inhabitants of Mars and Venus? A more attentive observation of the ashen-gray light of the moon, which appears to be principally produced by the reflection of the more or less luminous face of the earth, may perhaps one day provide us with an answer to our question.

Before quitting this subject, let us remember that both snow and frost are of great utility to the husbandman. The latter, by expanding the humidity with which the hard clods are penetrated, crumbles them into powder, and renders stiff land porous, friable, and mellow. It also clears the soil from the plague of insect life, which, if it increased without so powerful a check, would probably prove a terrible injury to the crops. Moreover, it so hardens in winter the moist soft ground as to permit of the necessary field operations being carried on. Snow, as Dr Child remarks,[12] is even more useful. It covers up the tender plants with a thick mantle, which defends them against the attacks of excessive cold. "God giveth snow like wool," and for somewhat the same purposes as wool. The mantle which so closely wraps about the gaunt limbs of the winter-stricken earth neither allows the internal heat to escape nor the external cold to enter in. It has been found that the inner surface of the snow seldom falls much below 32° F., although the temperature of the external air may be many degrees under the freezing-point; and it is known that this amount of cold can be endured by the crops without injury, so long as their covering protects them from the raking influence of the wind. In climates where the winter's cold is longer and more intense than in England, the protective influence of snow is much more plainly shown. Where it lies long and deep, it opens out routes that were impracticable in summer on account of their ruggedness, and prepares a smooth path for the sledge, or for the "lumberer," over which the largest trunks of the forest may be carried with ease to the river or canal.

In the polar regions (we quote from Dr Child) snow supplies the ever-ready material out of which the Esquimaux construct their houses, and hardy explorers extemporise the huts in which they find shelter when absent from their ships on distant expeditions. Nor are the ships themselves considered "snug winter quarters" until their sides have been banked up in walls of snow, and the roof raised over the deck has been thickly covered with it. Snow huts are warmer than might have been expected. If built upon ice over the sea, their temperature is sensibly influenced by the heat of the unfrozen water below, which is said seldom to fall much under 40° F. in any part of the ocean. Even where the external temperature has sunk to 20° or 30° below zero, sufficient warmth is produced in a snow hut by the huddling together of three or four persons within it. When Dr Elisha Kane, the American explorer, passed a cold arctic winter's night in a hut beyond Smith's Sound, the temperature produced by its complement of lodgers, and two or three oil lamps, reached 90° F.; so that he was compelled by the heat to follow the example of the rest of the party, and partially to divest himself of his clothing. Yet in lat. 79° N., Dr Kane marked a temperature of 75° below zero in the month of February. No fluid could resist it. Even chloric ether became solid, and the air was pungent and acrid in respiration.

Red Snow.

As if it had been ordained that there should be nothing absolute in nature, snow itself, the very type of whiteness, sometimes exhibits the most curious colouring. Who, for instance, has not heard tell of red snow? Its existence was even known to Pliny, the great Roman naturalist, and he attributed it to a dust with which the snow became covered after it had lain several days on the ground. "Snow itself," he says[13] "reddens with old age" (Ipsa nix vetustate rubescit).

Benedict de Saussure was the first who described red snow like a naturalist.[14] He observed it on the occasion of his ascent of Mont Breven, near Chamounix, in 1760; and was greatly astonished at seeing the snow tinted in various places of an extremely vivid red. "In the middle of each patch," he says, "was the greatest intensity of colour, and the middle, moreover, was of a lower level than the edges. On examining this red snow closely, I saw that its colour depended upon a fine powder which mingled with it, and which penetrated to a depth of two or three inches. This powder could not have descended from the summit of the mountain, since it was found in localities isolated and even remote from the rocks; nor did it seem to have been deposited by the winds, since it did not lie in drifts. One would have said that it was a production of the snow itself, a residuum of its thaw.... What at first suggested this opinion was the fact that the colour, extremely weak on the edges of each concave patch, gradually grew deeper as it approached the bottom, where the trickling water had carried down a greater quantity of residuum."

The learned Swiss naturalist found this red snow on many other mountains, and during a certain period of thaw, subjected it to various experiments, which led him to the conclusion that it was a vegetable matter, "a dust, or pollen, of the stamens of plants." Slightly odorous, it exhaled, during combustion, a scent not unlike that of sealing-wax.

Ramond met with red snow in the Pyrenees, at an elevation of 7800 feet. He discovered in it, when burnt on incandescent coals, the odour of opium or of chicory. He supposed that the little deep red lamellÆ which coloured the snow were mica, and looked upon the mica as a product of the decomposition of the rocks by the action of the sun and breezes of spring. But this opinion was overthrown by Captain Ross, who, in 1819, found red snow in Baffin's Bay (lat. 85° 54' N.), to a depth of thirteen feet, over a soil perfectly free from mica. Other explorers affirm that in those regions they have never met with the red snow more than three to four inches deep. Captain Parry, in his Polar voyage, found this coloured snow principally in the track of his sledges; and, agreeing with Sir John Ross, he supposed it to derive its redness from the presence of a kind of mushroom, of the genus Uredo, to which Bauer has given the name of Uredo nivalis.[15] According to experiments made by Bauer on specimens brought from the Polar regions, these tiny mushrooms are, on the average, a fiftieth of a millimÈtre in diameter; they develop themselves like vegetables; the youngest are sometimes colourless; when entirely freed from snow, they grow black under the influence of an intense cold, without losing their germinative faculty, and give birth, under the influence of a higher temperature, to a green matter.

Let us continue to examine the difference of opinion between naturalists.

De Candolle declared the red snow of the polar regions to be identical with that of the Alps, after having carefully compared the two. But he saw in it a genus of cryptogams, differing from the genus Uredo.[16] Robert Brown asserted that it was a kind of alga, allied to the Tremella cruenta. Azara was of this same opinion, except that, instead of a tremella, he recognised in it an alga of the genus Protococcus, which he called Protococcus kermesinus, because its colour resembled that of the kermes, or cochineal.

In the opinion of the observers whom we have cited, the colouring corpuscles of the snow belong to the vegetable kingdom. This opinion was supported by numerous adherents, and soon acquired so great an authority, that, in an assembly of naturalists at Lausanne, De Candolle overwhelmed with sarcasm a communication from Lamont, Prior of the Hospice of St Bernard, on the "animality of red snow." And yet this last hypothesis was not so rash as might have been supposed; for Dr Scoresby, to whom we owe a profound study on the crystalline forms of snow, had already attributed to an animal matter the colouring of the snow and polar ice.

Now-a-days, however, it may be regarded as finally settled that this phenomenon is due to the immense aggregation of minute plants belonging to the species called Protococcus nivalis;[17] so called in allusion to the extreme simplicity of its organisation, and the peculiar nature of its habitat. If we place a portion of the snow coloured with this plant upon a piece of white paper, says Mr Macmillan,[18] and allow it to melt and evaporate, we find a residuum of granules just sufficient to give a faint crimson tinge to the paper. Placed under the microscope, these granules resolve themselves into spherical purple cells, from the 1/1000th to the 1/3000th part of an inch in diameter. Each of these cells has an opening, surrounded by serrated or indented lines, whose smallest diameter does not exceed the 1/5000th part of an inch! When perfect, the plant is not unlike a red-currant berry; as it decays, the red colouring matter fades into a deep orange, and the deep orange changes into a dull brown. The thickness of the wall of the cell does not exceed the 1/20000th part of an inch! Each cell may be considered a distinct individual plant, since it is perfectly independent of others with which it may be aggregated, and performs for and by itself all the functions of growth and reproduction, having a containing membrane which absorbs liquids and gases from the surrounding matrix or elements, a contained fluid of peculiar character, formed out of these materials, and a number of excessively minute granules, equivalent to spores, or, as some would say, to cellular buds, which are to become the genus of new plants. There is something, adds Mr Macmillan, extremely mysterious in the performance of these widely different functions, by an organism which appears so excessively simple. That one and the same primitive cell should thus minister equally to absorption, nutrition, and reproduction, is an extraordinary illustration of the fact, that the smallest and simplest organised object is, in itself, and for the part it was created to perform in the operations of nature, as admirably adapted as the largest and most complicated.

Fig. 8.—Protococcus nivalis.

The Eternal Snows.

The epithet "eternal" or "perpetual," applied to snow, would appear to savour of the ambitious, if not of the profane. Can we say of anything which belongs to earth that it is "eternal?" Assuredly not. The earth has not always worn the aspect which it now wears, and, at a period not far distant from its origin, could not in any region have been covered with snow. Now, whatever has had a beginning cannot be eternal. Many authors have, for this reason, substituted for the word eternal the word perpetual. But the latter is equally inapplicable. Who will venture to affirm that our globe or its system will endure perpetually?

This difficulty, however, is one which need not particularly embarrass us. We have been long accustomed to look upon language as a simple mask, or, at least, as a very dubious interpreter of thought. And we shall, therefore, continue to use indifferently the words "eternal" and "perpetual."

Let us suppose that two travellers set out from the equator, that plane of separation between the northern and the southern hemispheres. Let us also suppose that each proceeds in a diametrically opposite direction to the other, pursuing his route along one of those meridian lines which divide the earth into longitudinal portions, like the slices of a melon (to compare great things with small). The following will be their climatic stages:—

At first the two travellers will each traverse a moiety of the torrid zone, limited below and above the Equator by two parallel circles,—in the northern hemisphere by the Tropic of Cancer, and in the southern by the Tropic of Capricorn. Do not let these appellations alarm you: they show, once more, the narrow connexity of the heaven with the earth; tropic, coming from the Greek t??p? signifies a return—the sun returns from his apparent excursions, after having passed from the tropics to the zenith. For these circles form the extreme limits of the sun's march towards the north and towards the south: they are the two solstices—the summer solstice, when the sun enters the zodiacal sign of Cancer, and the winter solstice, when it enters the sign of Capricorn. The torrid zone is the only one which is thus divided into two portions by the Equinoctial, and which the sun passes twice a year to the zenith, that is, to the point directly above the heads of the inhabitants.

After having crossed the tropics, one of our two travellers will enter the North Temperate Zone, bounded by the Arctic Polar Circle—the other, the South Temperate Zone, bounded by the Antarctic Polar Circle. Having passed the polar circles, they will find themselves speedily arrested by ice and snow which never melt—by eternal ice and snow. These inhospitable regions compose the two frigid zones, which cover, like two immense hoods (forming the 0·82 parts of the terrestrial surface), the one, the northern hemisphere, the other, the southern.[19]

In their progress through these various climates, our two travellers will arrive at a very curious comparative result,—that the southern hemisphere is colder than the northern. This difference becomes especially recognisable below the 50th degree of south latitude; so that, after passing the Antarctic Circle, the ice opposes the voyager's course with nearly insurmountable obstacles; while, in the northern hemisphere, the whaler frequently penetrates to Spitzbergen, situated much nearer to the Pole than to the Polar Circle. This is a general fact; we confine ourselves to putting it forward.

Let us now suppose that our two travellers, always ready to compare the results of their inquiries, accomplish the ascent of a very lofty mountain situated under the Equator, such as Chimborazo. In the course of their ascent, they will traverse the same climates and the same zones which had marked the stages of their journey from the Equator to the Poles: at their starting-point they will find themselves in the Torrid zone, then will come the Temperate and the Frigid zones, the latter rendered inaccessible by glaciers and eternal snows. These vertical zones of the mountain are characterised by vegetables and animals whose types are found in the corresponding horizontal zones of the terrestrial surface. But what is most remarkable is, that there exists between the northern and the southern slopes of the mountain the same difference as between the southern and northern hemispheres: the line of the eternal snows descends much lower on the northern than on the southern slope, in the same manner as, in the southern hemisphere, the polar ice advances much nearer the Equator than in the northern.

Such is the general view-point which we must adopt for the clearer comprehension of the details of observation. Of course, when speaking of the limit of the eternal snows, we refer only to the lower limit, that is to say, to the greatest elevation attained by the snow-line in the course of a single year. As for the upper limit, it entirely escapes us; for the summits of the loftiest mountains do not reach the atmospheric strata which, by virtue of their refraction, cannot contain any vesicular, aqueous, or condensable vapour.

The line of eternal snow which, at the poles, is found on the level of the ground, gradually rises as we approach the torrid zone, where it attains its maximum of elevation, from 13,000 to 17,000 feet. This phenomenon does not exclusively depend upon the geographical latitude, nor on the mean annual temperature of the locality: it is the result of an aggregate of diverse circumstances which we have not the space here to enumerate and discuss. We shall content ourselves with placing before the reader a table which will show the remarkable differences existing in the height of the perpetual snow-line in various places.

The Line of Perpetual Snow.

Latitude.	Place.	Height of Snow-Line.
(Degs.)
79 N.	Spitzbergen	0
71	Mageroe (Norway)	2,350
70 to 60	Norway (Interior of)	3,500 to 5,100
65	Iceland	3,050
54	Oonalashka (W. America)	3,510
50	Altai Mountains	7,034
45	Alps, The, N. declivity	8,885
45	Do., S. declivity	9,150
43	The Caucasus	11,863
43	The Pyrenees	9,000
40	Mount Ararat	14,150
36	Karakorum, N. side	17,500
36	Do., S. side	19,300
36	Kuen-luen, N. side	15,000
35	Do., S. side	15,680
29	Himalaya, N. side	19,560
28	Do., N. side	15,500
17	Cordilleras of Mexico	14,650
13	Ethiopian Mountains	14,075
1 S.	Andes, in Quito	15,680
16	Do., in Bolivia, E.	15,800
18	Do., in Bolivia, W.	18,400
33	Do., in Chili	14,600
43	Do., in Patagonia	6,300
54	Strait of Magelhaens	3,700

The Inhabitants of the Eternal Snows.

If men have the faculty of living under all climates, they make use of that faculty, as we know, with extreme reserve. They have never permanently inhabited the polar regions and the perpetually snowy summits of the mountains: it is only at intervals that a few pioneers have temporarily ventured thither. Starting from this fact, it was long believed that the zone of eternal snows was not inhabited by any living being. Even men of science admitted, as an article of faith, that where man could not fix his residence no animal could live. They made, however, a concession with respect to vegetables, and particularly as regarded the lichens and the mosses.

Well, observation and research conjointly, have erased this article of faith from the scientific code. It has been demonstrated that the icy regions, which man visits only at rare intervals, and where he sojourns but for a time, are the home of a certain number of animal species, more or less allied to the human species. The scientific exploration of these regions dates only from our own time. Spitzbergen, and the summit of the Alps,—such are our points of comparison.

It is difficult to conceive of anything more interesting than the historical exposition of the limited Fauna glacialis. First, let us take the discovery, comparatively recent, of a small rodent of the mouse order.

The Arvicola Leucurus, or Arctic Vole.

On the 8th of January 1832, a Swiss naturalist, M. Hugi, started from Soleure to study the winter condition of the classic glacier of Grindelwald. The undertaking was in many respects a difficult one; the sides of the Mettenberg, bordering on this glacier, were covered with an uniform stratum of hardened snow; a pathway had to be cut out with the pickaxe. M. Hugi and his companions did not arrive at the Stierreg until towards evening.

Fig. 9.—Among the Alps.

A goatherd lives there during the summer. They sought around and about for his little cabin, but, on the uniform white carpet of snow which covered everything, no sign of it could be detected. At length they came upon a little mound, which they immediately proceeded to excavate; and late in the night they discovered the roof of the hut. They then redoubled their efforts to sweep away the snow obstructing the door. On opening it a score of mice emerged from the cabin, some of which they killed.

For a picture of the poor victims we are indebted to M. Hugi. "These little rodents are of a yellowish gray, and very slender; from the head to the tip of the tail they measure about nine inches. The hind paws are of a length wholly disproportionate to the fore paws. The tail and ears are naked; their transparency is remarkable.... This animal," adds M. Hugi, "appeared to me completely unknown, and I do not remember to have seen it in any zoological collection."

After determining its genus and species, the intrepid explorer of the Alps was entitled to have given it a name; but this honour escaped him.

The same little rodent has since been found in many other parts of the Alps; notably among the rocks of the Grands-Mulets, some 12,500 feet above the sea-level.

Desirous of comparing the climate of Spitzbergen with that of the summit of the Alps, M. Martins established himself, in 1841, with his friend, A. Bravais, on the Faulhorn. "While," he says, "we were engaged in our experiments, we often perceived a little animal passing swiftly by us, and stealthily gliding into its burrow. We remarked that it was also found in the auberge, or inn, and that it fed upon Alpine plants. At the first glance, its resemblance to the common mouse led us to think that this inconvenient guest had followed man into his abode on the Faulhorn, as it had formerly crossed the seas on board ship. But a more attentive examination showed me that, far from being a mouse, it was a species of vole, which had hitherto escaped the researches of naturalists. I designated it by the name of the snow-vole, Arvicola nivalis."

It was the same animal which M. Hugi had discovered nine years before. The ice was broken, and names, both generic and specific, afterwards fell like hail on the body of our poor little rodent. Some would have had it called—

HypudÆus alpinus.
HypudÆus petrophilus.
HypudÆus nivicola.
HypudÆus Hugei.

Others, and fewer in number, preferred the designation of "White-tailed Vole,"—

Arvicola leucurus.

Others again, "the Lebrun vole,"—

Arvicola Lebrunii.

Which of all these names shall prevail? We cannot say, and it matters very little to us. Perhaps the nomenclators may in time agree among themselves upon the appellation of the genus. However this may be, we know—and it is an important fact—that a mammal exists at altitudes where men could not live, and that he is found in the Alps, above even the lower limit of the perpetual snows. Is it the only mammal which can live at such a height?

The Marmot.

Who, in the wide world of London, where so many waifs and strays are drifting with the great current of human life, has not observed the Savoyard wanderer with his dancing marmot? If the man did not attract our notice, his curious companion would. In form he belongs partly to the bear, and partly to the rat. Naturalists have, therefore, expressly created for him the genus Arctomys,—a Latinised Greek name, signifying "The Bear-Rat."

In fact, the marmot resembles Harlequin's cloak, or rather, if it be permissible to compare little things with great, the Austrian Empire,—a composite of territories and races; and Buffon has described him very aptly. He has, he says, the nose, the lips, and the shape of the head of the hare; the hair and nails of the badger; the teeth of the beaver; the cat's whiskers; the eyes of the dormouse; the feet of the bear, with a short tail and truncated ears.

Add to this that the marmot—he is a little larger than a rabbit—is omnivorous like man and the bear, with whom he shares his aptitude for dance and sport. While he eats any and everything, he nevertheless prefers vegetable food to all other kinds; and with his orange-coloured incisors gnaws the bark of shrubs. He rarely drinks, but when he does drink takes a hearty draught; is particularly fond of milk; drinks it by raising his head at each mouthful, like a hen, and giving utterance to an audible murmur of contentment, just as if he were reciting his Benedicite. Will it be in allusion to this characteristic that the common French phrase has originated, Marmotter des priÈres?[20]

During the summer the marmots inhabit the snowy summits of the Alps. At the beginning of autumn they descend to a lower level, for the purpose of excavating the burrows in which they pass the winter, completely benumbed by the frost. This is the time when the hunters easily capture them; they have nothing to do but to dig (creuser is the technical word); and frequently they are found as many as ten or twelve in the same burrow, rolled up like balls, and buried in a litter of hay. Their sleep, says De Saussure, is so profound, that the hunter deposits them in his sack and carries them away without awakening them. The Chamounix hunters, he adds, have already entirely expelled or destroyed the goats formerly so abundant on their mountains; and it is probable that, in less than a century, we shall see neither chamois nor marmots.

This prophecy of De Saussure's is on the point of being realised. Still, even at the present day, marmots are not very rare in the Valais and the canton of Ticino (du Tissin), where they are called Mure montane (mountain rats); a phrase from which is derived, without doubt, the appellation marmot. They prefer as their abode the stony islets which rise here and there in the midst of the rocks. The ears of travellers who venture into the barrenest recesses of the Alps of the Bernese Oberland are sometimes struck by a very sharp whistling, for which, at first, they find it difficult to account. It is the young marmot's cry of alarm; for the old appear to be deprived of this strident faculty.

For a considerable period only a single species was known—the marmot properly so called (Arctomys marmotta, Gmelin); but four others must now be added:—1st, The marmot of the Caucasus (Arctomys musicus), still imperfectly known; 2d, The marmot of Canada (Arctomys empetra), who clambers up the trees like a cat, and is distributed throughout all North America, particularly in Hudson's Bay, and Alaska, on the north-west coast; 3d, The Arctomys monax, who appears to be peculiar to Maryland; 4th, The Russian marmot (Arctomys citillus), of the size of a field-mouse, and of a brown colour, spotted with white; 5th, The marmot of Siberia (Arctomys bobac), smaller than the common species, of a yellow gray, and building vast burrows shaped like a funnel.

Will the reader permit us an allusion, in passing, to a question which we do not see discussed in books of natural history? Formerly among the treasures of ancient druggists figured a kind of panacea, called "Graetz's balls." What were these "Graetz's balls," at one time esteemed as a universal medicine, but no longer included in our pharmacopeia?

This was their origin:—The subterranean dwellings which certain species of marmots construct with so much skill, are each composed of two galleries, which unite together like the arms of a Y, and terminate in a cul-de-sac. There are found the globules of clay known as "Graetz's balls." They are an industrial product of our rodents, as M. Oscar Schmidt established in 1866, by close observation of the Arctomys bobac of the Zoological Garden of Vienna. The marmot creates these balls by scratching up the earth, and appears to amuse himself—a child's amusement!—by rolling them to and fro in his galleries.

The Chamois.

Must we omit this graceful ruminant from the number of mammals inhabiting the eternal snows? No; for it is not of his own will that the chamois has taken refuge upon the snowy peaks of the Alps. If we meet with him there, it is because he seeks to shelter himself from the destructive instincts of man.

The chamois is one of those animal species which, before a century, perhaps, will have disappeared; his bones will then figure in the palÆontological museums by the side of the skeletons of extinct species. There, too, will be displayed the famous chamois balls, each of the size of a nut, covered with a shining substance resembling leather, of an agreeable odour, and seeming to be a morbid dejection, composed of roots and other undigested matter. These balls, the bezoars of the old physicians, were regarded as a remedy against every ill the human flesh is heir to; it was even professed that they rendered soldiers invulnerable, and were a better defence against bullets than the finest armour ever wrought by the smiths of Milan. How precious a remedy for this epoch of civilisation, when man—is he much wiser than his supposed progenitor, the ape?—seeks to replace the cholera and the pestilence by the most terrific engines of destruction!

The birds inhabiting the inhospitable region of the snows are more numerous than the mammals. Let us briefly refer to a few of the more important.

The Eagle and the Wren.

In speaking of the eagle, Tennyson's noble lines to that "imperial bird" will occur to every reader, from the force and clearness of the picture which they present:—

The affection of the eagle for his "mountain walls" may be easily understood. This giant bird, with his carnivorous instincts, is endowed with a remarkable tenacity of life, and can exist in habitats wholly inaccessible to man. But it is strange that a bird, which is as common a type of humility as the eagle is of ambition, and which we almost always cite as a contrast to the eagle—we mean, the delicate little wren—should also be found among the snow and ice, the silence and solitude, of the loftiest mountain regions.

To study the flight of the eagle, we should repair to Alpine highlands. When he has reached a certain altitude of the atmosphere, the royal bird descends obliquely, as upon an inclined plane, with a rush and a din of wings, and at a speed of upwards of thirty-six yards per second. We assured ourselves of the accuracy of this fact during an ascent of Mount Hochkoerpf, in the canton of Glaris. The bird traversed in six minutes a space of 40,000 Swiss feet, which is equal to about forty yards per second. This result agrees, on the whole, with the observations of a traveller, who wrote in the Nouvelle Gazette de Zurich, on the 26th of August 1863:—

"A society of tourists set out from Corri to climb the StÜtzerhorn, which is 8400 feet in height. From the summit they perceived an enormous eagle, which, having taken his flight from Calanda, beyond the Rhine, directed his course towards the StÜtzerhorn, for the purpose of halting, after a certain inflection, on the side of the Rothhorn."

The duration of the flight was five minutes; the interval between the starting-point and the point of arrival, two French leagues and a half. In three hundred seconds, therefore, the eagle must have traversed a space of 3000 Swiss feet, which is equal to a speed of forty-five yards per second. Hence, the swiftness of the eagle's flight is nearly equal to the velocity of sound.

One of the most admirable descriptions of the habits of this bird with which we are acquainted, is furnished by the well-known naturalist Macgillivray:—

"There he stands"—on his lonely crag—"nearly erect, with his tail depressed, his large wings half raised by his side, his neck stretched out, and his eye glistening as he glances around. Like other robbers of the desert, he has a noble aspect, an imperative mien, a look of proud defiance; but his nobility has a cast of clownishness, and his falconship a vulturine tinge. Still he is a noble bird, powerful, independent, proud, and ferocious, regardless of the weal or woe of others, and intent only on the gratification of his own appetite; without generosity, without honour; bold against the defenceless, but ever ready to sneak from danger. Such is his nobility, about which men have so raved.

"Suddenly he raises his wings, for he has heard the whistle of the shepherd on the crag, and bounding forward, he springs into the air. Hardly do those vigorous flaps serve at first to prevent his descent, but now curving upwards, he glides majestically along. As he passes the corner of that buttressed and battlemented crag, forth rush two ravens from their nest, croaking fiercely. While one flies above him, the other steals beneath, and they essay to strike him, but dare not, for they have an instinctive knowledge of the power of his grasp; and, after following him a little way, they return to their home, vainly exulting in the thought of having driven him from their neighbourhood.

"But on a far journey, he advances in a direct line, flapping his great wings at regular intervals, then shooting along without seeming to move them. In ten minutes he has progressed three miles, although he is in no haste, and now disappears behind the shoulder of the hill. But we may follow him in imagination, for his habits being well known to us, we may be allowed the ornithological license of tracing them in continuance."

Homeward bound,—Mr Macgillivray continues,—after having supplied his own wants, he knows that his young must be provided with food. Therefore he sweeps across the moor, at a height of two or three hundred feet, bending his course to either side, his wings wide-spread, his neck and feet retracted, now beating the air, and again sailing smoothly along. Suddenly he halts, poises himself for a moment, stoops, but recovers himself without touching the ground. The object of his regards, a golden plover, which he spied on her nest, has contrived to elude him, and he does not care to pursue her. Now, then, he ascends a little, wheels in short abrupt curves, presently rushes down headlong, assumes the horizontal position when close to the ground, prevents himself from being dashed against it by expanding his wings and tail, thrusts forth his talons, and grasping a poor, terrified ptarmigan that sat cowering among the gray lichens, squeezes it to death, raises his head exultingly, utters a clear, shrill cry, and, rising from the ground, pursues his journey.

As he passes a tall cliff overhanging a silent lake, he is attacked by a fierce peregrine falcon, which darts and plunges at him, as if resolved to deprive him of his booty, or drive him headlong to the ground. A more formidable foe is this than the raven; and the eagle, with a scream and a yelp, throws himself into postures of defence, until, at length, the hawk, perceiving that the tyrant has no intention of plundering his nest, leaves him to pursue his course without further molestation. Over dense woods, and green fields, and scattered hamlets, the eagle speeds; and now he enters the long river-valley, near whose upper end, cradled in mist, rises the rock of his eyrie. About a mile from it he meets his mate, who has been abroad on a similar design, and is returning with a white hare as her spoil. With loud strident cries they congratulate each other, cries that alarm the drowsy shepherd on the green strath below, who, remembering the lambs carried off in spring-time, discharges at them a volley of maledictions.

Their nest is of considerable size, but rudely constructed; a pile of twigs and heather and dead sticks, somewhat hollow in the middle, where lies a thin deposit of wool and feathers. Here repose the eaglets, two in number, and clothed in soft white down.

Independently of the species which, like the Pandion haliÆtus, and the Aquila nÆvia, inhabit the lower regions, the eagles which visit the Alps are very remarkable. Thus, the species of GypaËtos, which the inhabitants designate under the name of the Lammergeier, or "Lamb-slayer," is the European condor. The spread of his wings is about ten feet; he weighs from eighteen to twenty-four pounds, and can easily carry off in his talons kids, lambs, and even children.

The Steinadler, which, like the preceding, belongs to the inaccessible mountains of the cantons of Glaris, Schwyz, the Grisons, Appenzell, and Berne, would seem to be a variety or sub-species of the Aquila imperialis. The inhabitants of Eblingen, a village on the borders of the Lake of Brienz, hunt him vigorously. Finally, some eagles there are which only sojourn in the Alps temporarily; they appear to be astray; such are—

The CircÆetus leucopsis, which has a particular affection for serpent-haunted districts;

The HaliÆtus leucocephala, with head and tail of a milky white, belonging to the north of Europe and America; and

The Neophron percnopterus, or Egyptian eagle, of carrion-like odour, which is sometimes met with in the neighbourhood of Geneva.

The tawny-headed vulture (Vultur fulvus), and the ashy vulture (Vultur cinereus), with gray-brown mouth, and a brownish collar round his bare neck, are extremely rare in Switzerland.

But we now take leave of the eagle, and turn our attention to the lowly wren, whose charming but simple music has been described in charming but simple verse by Bishop Mant:—

The wren here referred to is a British species, the common wren, or Troglodytes vulgaris, one of the smallest of our British songsters; a restless, lively bird, which twitters about the hedgerows in summer, and about the garden and shrubbery in winter, and chanting his mellow song even under the gloomy sky of December. Allied to this familiar bird is the Gold-crowned Knight,[22] or Sylvia regulus, which is found in the Alpine deserts at an elevation of 9000 to 10,000 feet. Like our own Jenny Wren, he has a very fine, slender bill, which denotes his insectivorous propensities. He is easily known by the little crest of silky feathers which he wears on his head, like a diadem, and also by his peculiar cry of souci-Î-Î-Î.

Our crowned knight is very partial to the society of the tits, and, like them, he is easily caught with birdlime. He is so fond of the company of other birds, that, when he finds himself alone, he becomes disquieted; his prolonged tiny chirp grows plaintive; and he flies to and fro in quest of comrades. He may be regarded as a trustworthy barometer, for, prior to rainy weather, his song is very loud and incessant. Devoted to the pursuit of insects or their larvÆ, he seems to pay no attention to the passer-by; he flutters vivaciously from branch to branch, and puts himself in all imaginable positions, sometimes with his head upwards, sometimes with his head downwards. We have often watched, with extreme gratification, the acrobatic tricks of our Lilliputian gymnast. Occasionally, before he perches, you will see him, in a frenzy of indecision, rapidly agitating his wings, and revolving them like a wheel. If you look at him, while thus engaged, against the light, you will think you see a tiny, ethereal, diaphanous spinning-top. After "assisting" at such a spectacle, which the first wood will furnish, you will not be indisposed to admit with us, that the bird designated by the Greeks t???????, or "little wheel," and whose identity has so often been discussed, was, in reality, our golden-crested knight. Moreover, he is a true cosmopolite, in every acceptation of the word. Not only does he never quit us, not only does he remain faithful to us throughout the year, but we meet with him over all Europe. He is also found in Asia, and even, it is said, in America, from the West Indies to Canada. His flight being very short, it is supposed that he passed from one hemisphere to another by way of Behring's Strait. It is certain, at all events, that he discovered the New World before Christopher Columbus.

During the severe cold of the winter of 1867-8, we saw our knight—a very rare circumstance—haunt the vicinity of our houses, though he prefers the green shade of the forests, and especially of the forests of pine and fir. He who has seen him pecking at the bark and leaves of these trees, while the ground was covered with snow, and during a frost of 10° below zero (C.), will feel no astonishment at meeting him upon the snowy summits of the Alps.

Yet this pet bird of ours, this Lilliputian warbler, does not weigh more, with all his feathers, than a quarter of an ounce, or the two thousandth part of an eagle. Away with the hunter who would attempt such tiny game! A bird so small that he glides through the meshes of a net,—so delicate, that if you would not irreparably injure your "specimen," you must shoot him with a few grains of finest shot,—a bird of such frail appearance, withstanding all climates, and distributed over the entire surface of the globe,—here is a subject worthy the meditation of man, who pretends to be the "lord of creation!"

The Snow-Bunting—(Emberiza plectrophanes nivalis).

This is the snow-lark-bunting of Macgillivray, and a species of the genus Plectrophanes. In Scotland, he is frequently called the Snow-flake, and, in other parts of Great Britain, the Snow or Oat-fowl. His weight does not exceed an ounce and a half. His bill and legs are black; his forehead and crown white, with an admixture of black on the hind part of the head; black are the back and sides, but each wing is marked by a broad belt of white; the quill feathers are black, with white bases; the secondaries are white, with black spots on the interior webs.

The snow-bunting's favourite localities, where he loves to build his nest, are the crests of inaccessible rocks, surrounded by vast fields of snow, in whose midst the sun and tempest have created a few oases. The most he does is to approach the hospices of Monts St Bernard and St Gothard, and construct his nest under the eaves of their roofs. This nest, made of long blades of grass, is lined internally with hair and the feathers of poultry. At the beginning of May, the female lays six eggs of a snowy whiteness, and the male assists in hatching them, and bringing up the young. The bill of the latter is, at first, of a bright yellow, which turns black, like that of the parents, as they grow older.

The snow-bunting rarely descends into the wooded region. Of a very sprightly disposition, he spends nearly all his life in the midst of the snows and the ice. His song somewhat resembles that of the finch, which he also resembles in size and social instincts; for he may frequently be seen in numerous bands hovering above the highest mountains.

The snow-bunting is also met with in the northern districts of Asia and America.

The Red-Billed Crow—(Corvus pyrrhocorax).

The familiar cry of this bird, who resembles the thrush,—the krapp-krapp of the red-billed crow (la corneille des nieges),—agreeably falls on the ear of the traveller, when wandering through solitudes devoid of any other living being. By their cries and their presence these birds animate the denuded rocks which rise like promontories in seas of ice. They are easily distinguished from other species by their coral-red bills; whence their name of Pyrrhocorax. They nest in troops in the crevices of the most inaccessible rocks, and propagate there from generation to generation. Their presence is indicated by enormous heaps of ordure, veritable guano, which might well be used for manure. Their abrupt ascents and strident cries are signs of bad weather, which the mountaineer knows how to profit by.

If caught when young, these birds are easily domesticated. M. Tschudi, in his "Life among the Alps," relates the history of one who had been tamed. He would himself go in quest of the bread, cheese, and fruits which composed his repast; then, holding in his claws the prize he had coveted, devour it with avidity. What remained of his meal he carefully concealed in paper, and would gallantly defend the hidden treasure against whomsoever dared to approach it, against dogs as well as man. Fire had a singular attraction for him; he would extract from a lamp the burning wick, and swallow it without sustaining any injury; he would swallow even the dÉbris of the charcoal as he fluttered about the chimney. He showed an excessive joy at the sight of smoke, and loudly clapped his wings. Whenever he caught sight of any burning coal, he did not fail to pick up immediately all the paper, rags, or twigs he could lay his claws on; these he would place in the stove, and amuse himself by watching the smoke they gave forth. If a stranger entered the room, he gave vent to the most deafening cries, though he was exceedingly gentle and familiar towards persons with whom he was acquainted. His friends and favourites he distinguished in a peculiar manner; he ran in front of them, displayed his joy by expanding his wings, and alternately perched himself on their hands, their head, their shoulders, eyeing them all over, and bending his head as if to kiss them. Every morning he entered his master's bedroom, called him by his name, posted himself on his pillow, and waited tranquilly until he awoke; then he expressed his satisfaction by all kinds of gestures and noises.

Reptiles.

Close to the line of perpetual snow a black variety of vipers has been met with; but none of the serpent race ever cross that line.

The only reptile found within the boundaries of the snowy region is a kind of lizard (Zootoca pyrrhogastra), the only one, perhaps, of all the vertebrata which could live at an elevation above the sea-level of more than 9500 feet, buried in the snow for upwards of ten months.

During the few bright summer weeks, he feeds upon some rare insects and spiders.

The frigid zone is so far the natural habitat of these lizards, that they would rather die of hunger than live in the more genial regions to which men have wished to transplant them. In length they nearly equal our common lizards, but they are not quite so big; their back is of a chesnut brown, marked with black streaks and dots; the throat is bluish; the belly of the male is of a greenish blue, spotted with black, while that of the female is of so lively a red as to have suggested the name of the species, Pyrrhogastra; just as the name of the genus is derived from the circumstance that the young are hatched in the mother's belly, and are born alive like the young of a mammal. This statement, too, holds good with respect to the viper, which also endures the cold of elevated regions.

Inferior Animals.

Our information is still very incomplete so far as relates to the molluscs, the arachnida, and the insects which inhabit the frigid zone. The Alpine snail (Helix Alpicola), so remarkable for its transparency, appears to be the sole mollusc which, in certain localities, attains to an elevation of 7000 feet. It is, however, surpassed by the earthworm, which is not only distributed over the surface of every country, but ascends to the snowy summits of the loftiest mountains. Few animals have their geographical distribution so extended both horizontally and vertically; and only some species of spiders and millepeds keep company with the earthworm.

Among the other inhabitants of the snows have also been observed a dozen species of butterflies,—nearly all diurnal,—for the phalÆnÆ (?), or nocturnal Lepidoptera, appear to be much more sensible to the cold. M. Agassiz saw the "Little Vulcan" (Vanessa urticÆ) fluttering in the snowy desert which borders on the glacier of Aar, as if it were completely in its element. The wings of the majority of these butterflies are sombre-coloured; their caterpillars live upon the auriculas, and seem to accomplish their metamorphoses in regions uninhabitable to us. The leaf-wasp (Tenthredo spinacula) appears to deposit its larvÆ, at a height of nearly 10,000 feet, in the galls of the Alpine rose (rhododendron ferrugineum and rhododendron hirsutum.)

The coleoptera have also numerous representatives in the region of perpetual snows, with this difference—equally characteristic of other animals—that, upon the southern declivity, they ascend 1000 to 1500 feet higher than on the northern. We may mention, as specially distributed in the topmost zone of the Alpine world:—

The Chrysomela salicina, a pretty little beetle, sometimes blue, sometimes deep green, and finely punctuated, which lives almost exclusively upon a species of dwarf willow (Salix retusa).

The Nebria Escheri, a black beetle, about two thirds of an inch long, with feet and antennÆ of a brownish red; and

The Nebria Chevrierii, with rust-coloured feet and antennÆ, common in the sources of the Rhine.

Special mention must be made of the Snow-Flea. Do not think we are referring to an insect of the same species as our common fleas: the snow-flea approximates much more closely to the lice family than to the fleas, though it hops like the latter. The history of its discovery dates back as far as 1839. At this epoch, M. Desor, a learned Swiss naturalist, had undertaken some researches upon the glaciers. Accompanied by some friends, he set out from the hospice of the Grimsel, and arrived in the vicinity of the glacier of the Lower Aar. He had commenced his observations, when suddenly he heard Agassiz calling him, and shouting, "Come, come, make haste; here are your Mont Rosa fleas." Desor ran to the spot, and saw under a stone the little creatures whom Agassiz persisted in taking to be veritable lice, pretending they had been accidentally brought to these heights.

"I recognised with extreme joy," says M. Desor, "the little creatures whose loss I had regretted a year before. They are not pretty, but, on the contrary, very ugly. However, they showed, in opposition to the opinion of Agassiz, that they really inhabited the glacier, and were not merely chance visitors. We found them by thousands under other stones. ... Our guide, with whom the glaciers were old acquaintances, had never seen them before, and the tiny creatures excited his astonishment. What surprised us most was the rapidity with which they penetrated into even the most compact ice, till they resembled blood-corpuscles circulating in their vessels. This fact shows that there exist, in the hardest and most transparent ice, certain capillary fissures which escape an unskilled eye: it also proves that the glaciers, on their surface, and down to a certain depth, are by no means incompatible with the development of organised beings."[23]

The tiny insect in question was at first baptized by the name of Desoria saltans (order of the ThysanourÆ of Latreille), but has since received definitively the name of Desoria glacialis. It belongs to the family of the PodurÆ, singular creatures which, by virtue of their form, are a link between the earwigs and the spiders.

These are its generic characters:—

The body elongated, cylindrical, garnished with long setiform hairs, and composed of eight segments, six of which are perfectly distinct, and two (the two latter) very short, and scarcely perceptible; four-jointed antennÆ, longer than the head; long, slender, cylindrical feet; forked tail, silky, and transversely wrinkled; seven eyes, laterally grouped at the base of each antenna; body without scales.

The Desoria glacialis, a species at present unique, is of a velvety black, and about one-sixth of an inch in length.

The Podura plumbea (or "Spring Tail"), common enough in England, and found under all kinds of stones, will give the reader an idea of the flea of the glaciers.

On comparing these two species, we remark, first, that the Podura plumbea is somewhat longer and thicker in body than the flea of the glaciers (see Fig. 16; a, natural size; b, enlarged); but it is more particularly by the length of its antennÆ that we distinguish it. It owes its specific name of Plumbea to the livid blue or leaden colour of the scales which cover its body. These scales resemble those of butterflies; only they are much smaller, more finely situated, and very variable in form and size (Fig. 17). In catching it great care is required, for it is so easily crushed; it is, besides, very soft to the touch, though, when examined with a microscope, it is seen to bristle all over with hairs, apparently very hard.

Our podurÆ have also the faculty of leaping, and cling by thousands to humid places, especially to mosses and the under-surface of stones. The mechanism of their leap is explained by the presence of a forked, flexible, and elastic appendage, lodged in a kind of ventral groove beneath the last segments; by projecting this rapidly behind, the whole body of the animal is thrown forward. At the slightest contact the insect folds up its caudal appendage under its belly, and you would then suppose it did not possess one. This circumstance explains why, in many books of natural history of good repute, the podurÆ, and especially so common a species as the Podura plumbea, are represented without this characteristic instrument.

Herbaceous Plants which best endure the cold of Winter.

The "way to look at things," which is the true foundation of science, varies, not only according to a man's degree of intellectual cultivation, but according to his social condition or profession. The herborist has eyes only for the plants in which he deals,—the "simples" which, as we read in old Gerarde, wrought such wonderful cures in the days of our forefathers,—and from the most exquisite flowers he turns with indifference. The gardener, on the other hand, is wholly absorbed by his love and his hate,—his charming exotics, and his troublesome weeds. The latter he regards with much the same feelings as a society wholly composed of honest men would regard an infusion of the "dangerous elements;" for weeds, like rogues, take what is not their own, and deprive others of their means of sustenance. But to classify plants according to their virtues or vices is not worthy of science, exclaims the rigid botanist. Would you mingle vile self-interest with the pure study of the vegetable kingdom? Remember that all selfish feelings ought to be banished from the sublime sanctuary of analysis and synthesis.

This sounds exceedingly well. Disinterested words, from whatever quarter they come, always produce—perhaps, on account of their comparative rarity—an admirable effect. But what is their real value? To ascertain it, the listener must be able to seize, like so many luminous threads, all the emotions which are acting upon the heart and tongue of the speaker. But we are very far from having arrived at this degree of perfection. Shall we ever attain to it? Yes, because we can conceive its possibility. But, until that golden epoch, the pure love of science will always remain a myth, and we shall not have universally understood the necessity of seeking in the profound study of nature the grand destiny of man.

It is among the weeds and noxious plants that we shall find the species capable of enduring longest the cold of winter. What part, then, do they fulfil in the economy of creation? An ambitious, but not a novel question, which has often been propounded in reference to our parasitical insects.

The best answer which we can make to it is this: Everything invites us to work. Labour is imposed even upon him who least desires it. Earth will yield a return only in proportion to the care we bestow upon her.

If, after having toiled and sown, we had nothing to do but to gather in the harvest, every person would become an agriculturist. But a soil which is not manured will soon grow exhausted; and if it be neither ploughed nor harrowed, instead of barley or vegetables, it will soon be covered with tares; rank weeds will flourish in every field. Such is the chastisement reserved for sloth,—the true "original sin" of the human race.

Well, then, it is among the weeds, everywhere so common, that we meet with the plants best able to brave the rigours of frost.

The Dog Mercury.

The annual Dog Mercury (Mercurialis annua) is one of the most tenacious. It attracts the passer-by, if he condescend to bestow a glance upon it, only by its extreme abundance; it propagates very largely, though it is by no means partial to all localities. For instance, it avoids the woods as persistently as its congener, the common Dog Mercury (Mercurialis perennis) seeks them. It prefers the vicinity of human habitations and uncultivated fields. If let alone, it spreads with a dangerous rapidity, and invades every garden which is not kept in the most exquisite order. Still, we must not deal too harshly with it. It is not altogether unfriendly to man. In truth, owing to its laxative properties, it renders him invaluable services. The country people have great faith in fomentations of Dog Mercury and honey. Understand, we pray you, that not an atom of mercury enters into it, despite its significant name; but a decoction of the annual Dog Mercury, mixed with a little thick honey, answers all the purposes of those lenitive clysters which are so beneficial to excitable temperaments. The leaves of the plant are eaten in Germany like spinach.

Of the Mercurialis perennis Mr Sowerby writes:—"This plant was formerly used in medicine, but has long been abandoned as a remedy. It is extremely acrid, and even poisonous, though recommended in some old books as a good pot-herb, probably from being confounded with the annual species. When steeped in water, the leaves give out a fine blue colour resembling indigo. This colouring matter is turned red by acids, and destroyed by alkalis, but is otherwise permanent; it might possibly prove valuable as a dye, if any means could be discovered of fixing it, and the herb has been introduced into this work with the view of drawing the attention of chemists to the subject; no experiments seem to have been lately made upon it."

Let us now advise you how to distinguish our medicinal plant from the "ill weeds" with which it loves to associate. Its ovate, rough, irregularly-dentated, and petiolated leaves would not give it a sufficiently marked character, had it no other features peculiar to itself. But observe the yellowish-green glomerules, arranged, like millet, on a long frail spike. (Fig. 18, a.) They exhale, as your nose will inform you, a peculiar aroma, like that of spiced bread: no other plant but our Dog Mercury is gifted with this odour. Now, bring your magnifying-glass to bear upon it; with the point of a knife or a feather open one of the grains which form the glomerules of the spike; out of it will leap, as if impelled by an invisible spring, a large number of stamens, easily distinguished by their elastic thread-like anthers, covered with tiny yellow beads. Each greenish grain is a flower; the calyx, which also serves as the corolla, is represented by three little petals, forming the external envelope of the little flower. (Fig. 18, b.) But something essential is still wanting; in the centre of the stamens you do not find any pistil. Why is so important an organ wanting? Because our little rounded flowers, with their spice-bread odour, have but one sex, are unisexual; they are male flowers, since they are furnished only with stamens. In vain do you hunt on the same stem for their companions, the female flowers. You will find them only upon other stems, distinct from those which bear the male flowers. The Dog Mercury, then, is a plant whose two sexes are lodged in two different houses, ?????—is, in fact, a dioecious species.

But you are sure to find the female flowers in the immediate neighbourhood of the stems with the male flowers. They are easily recognised by their larger and darker leaves (Fig. 18, c); and especially by their little twin pods, green, wrinkled, and pedicellate,[24] which garnish the axil of the leaves. (Fig. 18, d.) From this characteristic the female mercury was formerly mistaken for the male; and many centuries elapsed before naturalists recognised, what now-a-days seems so simple, that the little pods, joined in couples, and containing each a grain, composed the fruit of a single plant; that every fruit proceeds from an ovary; and that every ovary is a sign of the feminine sex.

In the Historia Naturalis of Pliny, who was at once so acute and so credulous an observer, we first meet with the name of Mercurialis.

"The plant is so denominated," he says,[25] "because it was discovered by Mercury. Its juice, mingled with that of the hibiscus (a species of the MalvaceÆ) and the purslain, forms a kind of unguent, with which, if you thoroughly rub the hands, they can touch molten lead without being injured."

The description which Dioscorides[26] gives of the Linozosis, which he also calls Parthenion, or Mercury's Plant (???? ?t?????) applies, in the main, to our Dog Mercury. It is true that its leaves "are not like those of the basilic" (f???a ???a ????); but they resemble in all respects those of the smooth variety of cultivated mint; and, apparently, the basilic of Dioscorides was one of our mints. The fruit of the female, he adds,—evidently meaning the male flowers,—are disposed in clusters.

Both species of the Herb or Dog Mercury belong to the family EuphorbiaceÆ.

Our attention must now be directed to another point. It is a fact, that in winters of moderate severity the Mercury continues to infest our gardens and cultivated fields. It only succumbs to a frost equal to six to ten degrees below freezing-point; then its congealed stem totters, and grows black, and its leaves mingle so completely with the soil that it is difficult to discover any vestiges.

How singular a contrast! The plants most destructive in our kitchen gardens are frequently the most useful in medicine. There are no drugs more popular than the weeds which we call Herb Mercury, Garden Nightshade, and Dog's-tooth grass. All belong to families whose properties are strongly marked. As already stated, the Mercury ranks among the EuphorbiaceÆ, remarkable for their acrid and more or less purgative juice. In this family occur the most violent drastics, such as the Croton tiglium, whose oil (expressed from the seeds) has long been considered an efficacious medicine. The Garden Nightshade is one of the SolanaceÆ, and cousin-german of the useful potato; and the Dog's-tooth grass, whose roots compose three-fourths of our possets, is of the same family as our cereals.

The Garden Nightshade.

Fig. 19.