While the wide range of the English language over the globe is of considerable advantage to commerce, and possibly to some other interests, it is the source of some perplexity when, as in treating of natural history or botany, precise terms have to be employed. Thus in the United Kingdom most people know exactly what tree is meant by the silver fir; but in the United States, with a population well on to double that of the British Isles, the silver fir is understood to mean quite a different species—namely, Abies venusta, a native of California, not suitable for forestry purposes in this country. In like manner, though there is no true cedar indigenous to America, there are half-a-dozen trees there known as red cedar, white cedar, and so forth. English, being a living language, is still fluid; meanings shift with changes of environment; to secure precision, therefore, science must have recourse to classical Greek and Latin, which, being dead languages, change no more.

The group of evergreen conifers, then, collectively known as silver firs, consists of about thirty species comprised in the genus Abies; and these are most easily recognised by the position of the mature cones, which stand erect on the branches, whereas in the other group of true firs, the spruces (Picea), they are pendulous in all except two or three Asiatic species. Another mark of distinction is the circular base of the needle or leaf, which, when it falls or is pulled from the branch, leaves a perfectly circular scar; while in the spruces the leaves are set upon little pegs which remain on the twig when the leaves fall. The grey or silvery bands on the under side of the leaf, although it is from these that the tree is called the silver fir, are not an exclusive badge of the genus; for some of the other firs, notably the Manchurian spruce, display similar colouring.

The tree known in this country as the silver fir par excellence (Abies pectinata) is the loftiest European tree. Probably the extreme height had been attained by one grown in a Bosnian virgin forest, measured by Mr. Elwes after it had fallen, "over 180 feet long, whose decayed top must have been at least 15 or 20 feet more."

The silver fir is not a native of Britain, having been introduced about the beginning of the seventeenth century. Its range extends over southern and central Europe, from the Pyrenees on the west to the borders of Wallachia on the east. Nevertheless, it has found a congenial home in these islands, where, if it had ever received scientific handling, it would have been far more highly esteemed for its timber than it now is. Such handling we have never given it; the silver fir has been used indiscriminately in mixed plantation, where, outstripping every other tree in stature, it loses its leader, and sends up a number of heads which get battered by the wind, becoming ragged and unsightly.

Now if these noble firs, instead of being scattered among trees of inferior height, were planted in close forest, so as to be drawn up with clean boles to a single leader, they would protect each other from the gale. Then might be seen something of the true character of the silver fir as it is developed in such forests as that of the Vosges, in Eastern France, where a tract fifty miles long is clad principally with this species, or in the Jura, where a forest of silver fir 10,600 acres in extent yields annually 170 cubic feet of timber per acre felled. British foresters and wood merchants set a low value on such timber as the silver fir produces in this country; and small blame to them, because, grown as we are in the habit of growing it, branchy and full of great knots, it is almost worthless; but in some districts of Europe where silver forest is well managed and felled in rotation, the deals are more sought after and command a readier market than spruce. The thinnings make excellent pitwood, and although, like spruce, the timber is not naturally durable enough for outdoor purposes, it can be made so by creosote treatment.

The silver fir sows itself very freely in places where the ground herbage is not so rank as to choke the young plants; but to allow natural reproduction a fair chance, ground game must be rigorously excluded, for deer, hares, and rabbits seem to regard this delicacy in much the same light as human beings do asparagus. This tree—Abies pectinata (I must resort to Latin to distinguish it from the other European, Asiatic, and American silvers) differs from every other member of the genus (so far as my observation goes) in being a shade-bearer; that is, it will grow under the shade and drip of deciduous trees, so dense as to be fatal to the health, and generally to the life, of every other conifer except the juniper. This renders it of almost unique utility for under-planting, the beech being its only rival for that purpose. It is true that the Douglas fir and the giant Thuja both stand a considerable amount of side shade, but the silver fir thrives under conditions of overhead drip which the others cannot suffer. One may read in books on forestry that the Norway spruce is patient of overhead shade; I can only say that, though I have sought diligently for an instance of its doing so, and have seen many thousands of spruce planted in faith of this misleading advice, I have never found a case where the attempt has succeeded.

In planting silver firs it is important to take advantage of their power of bearing shade, for the young trees are very susceptible of injury by late frost, from which older and taller woodland will protect them. It is remarkable how long and patiently the young silvers so treated will wait for head-room—marking time, as it were, till the older crop is cleared away, when they will go ahead and occupy the ground.

The silver fir is more exacting in the matter of climate than in that of soil. The great forest of the Vosges is chiefly on silicious ground; but that of the Jura, which is even finer, grows on limestone. The great silver firs at Rosneath, probably the oldest in the United Kingdom, stand near the sea level in deep sandy soil. They are certainly over 200 years old, the largest being about 110 feet high and 22 feet 7 inches in girth. These trees are very massive, and branch into great heads owing to their not having been grown under conditions of close forest. The only rival in bulk to them is to be found at Ardkinglass, on Loch Fyne, about 120 feet high, and estimated to contain over 1,000 cubic feet of timber.

In many places on the south and east coasts the silver fir does not thrive. It requires an abundant rainfall and a moist atmosphere, which probably accounts for its inability to stand the climate of the Eastern United States. There are, however, some fine specimens in Sussex (at Cowdray there is, or was a few years ago, a silver fir over 130 feet high, with a clean bole of 90 feet), and at Alnwick, in Northumberland; but at Novar, so famous for coniferous trees, Sir Ronald Munro Ferguson has given up planting it owing to its inability to resist the attacks of aphis. This seems to indicate a constitution impaired by climatic influence, for insect parasites, though they certainly hasten the death of a weakly subject, are not likely to prevail over a thoroughly vigorous one. In Western Scotland, where, as in Ireland, the silver fir makes grand growth, aphides swarm immediately upon any tree that has been debilitated by late frost or other injury. On the other hand, the Caucasian silver fir (Abies nordmanniana), which thrives splendidly in many parts of Britain where the common silver cannot be grown, frequently succumbs in the west to the attacks of aphis. At Benmore, on the Holy Loch, about 2,000 acres were planted about forty years ago with different kinds of conifers. I have examined the lists of the species planted, and find that by far the largest proportion consisted of this Caucasian fir. The forest remains, a splendid monument to its designer's enterprise; but hardly a Caucasian fir is to be found in it. The prevailing species are Douglas fir and giant Thuja.

Dr. Stewart M'Dougall has made some useful research, leading him to identify the silver fir aphis with Chermes abietis, the spruce louse which, as explained when treating of the larch, migrates to the larch and produces parthenogenic generations thereon. Dr. M'Dougall traces the silver fir louse to the same parentage. It follows from this that the spruce is a dangerous neighbour to silver firs.

Less serious, because not hurtful to the general health of the tree, is the "witch's broom" which forms upon the silver fir, sometimes greatly disfiguring it. This is caused, or at all events accompanied by, a fungus (Æcidium elatinum), which passes one phase of its existence upon certain humble herbs of the Pink family, such as the mouse-ear chickweed and sandwort.

For purposes of timber probably the common (A. pectinata) and the Caucasian silver fir (A. nordmanniana) are the pick of the genus, but there are also many other species of singular beauty. Their beauty, indeed, especially in a young state, has proved somewhat of a snare, inducing people to plant them in gardens and pleasure-grounds where they soon outgrow their environment, and, being isolated from their kind, are apt to send up many leaders and so forfeit their true character. Several years ago I was staying in a country house in the south of England, where a royal personage was paying a visit. It was arranged that the said personage should plant a memorial tree; a site was selected on a close-shaven lawn, and I could not but deplore the tree chosen for the honour. It was perhaps the least majestic of all the silver tribe, namely, the Spanish fir (A. pinsapo), a species which seldom responds freely to the conditions provided in this country, and, when it does so, is of gloomy appearance.

The largest silver fir in the world is the North American (A. grandis), which in a young state might easily be mistaken for A. pectinata, but soon exhibits its true nationality by the extraordinary rapidity of its growth. It races upwards at the rate of three feet a year, and, distancing all surrounding growth, suffers the penalty inevitable in our stormy climate, unless it should be provided with shelter from a sufficient company of its peers. At the Avondale School of Forestry A. grandis is reported to be less liable to injury from spring frost than the common silver fir. No doubt there are spaces in the wilder parts of this island where this grand tree might be grown into splendid forest, but as an isolated specimen it can never develop its true dimensions, which are out of all proportion to our native woodland. The timber is neither strong nor durable; indeed, of the nine species of North American silver firs, Professor Sargent reports favourably in this respect upon one only, Abies nobilis to wit, a tree of which, personally, I have formed a very high opinion for the climate of the northern and western parts of the United Kingdom. It has suffered in reputation with many experienced planters, owing to a liability to lose its leader when it outgrows its surroundings, as it very speedily does; but, as in the case of the common silver fir, that is the consequence of bad forestry; if A. nobilis were planted in masses, the trees would protect each other. No forester can look unmoved at the group at Murthly in Perthshire, several of which are well over 100 feet high. This fir is also exceedingly ornamental in a young state, some of the seedlings from every sowing having foliage with a lovely glaucous bloom. A. magnifica and A. amabilis are not easily distinguished from A. nobilis in a young state, until cones are produced. They are beautiful, but comparatively useless trees, and there are no specimens in this country approaching the dimensions already attained here by A. nobilis.

Of the Asiatic silvers I will mention but two, both from the Himalayas. Abies pindrow, a beautiful tree of columnar growth and fine glossy foliage, has proved quite hardy in Britain. The finest specimen I have seen is at Gordon Castle, Banffshire, about 70 feet high and a picture of health. A. webbiana is a tree of wider spread than A. pindrow, and excels all other silvers in its splendid foliage, two broad white bands on the under sides of the large needles thoroughly justifying the epithet "silver." When the boughs are set with great violet-blue cones this tree is indeed a beautiful object. Individuals of this species vary a good deal in their endurance of British climate, at least in the west. Its tendency to early growth renders it very vulnerable by spring frosts, and when it has been debilitated by the destruction of the young growth, it falls a prey to the attacks of aphis.