In conclusion, a few general remarks may be made, the observance of which will usually ensure success in the formation of an Aquarium. In the first place, if the vessel in which the Aquarium is to be established be home-made, care must be taken not to use any cement that has a disagreeable smell—which would be very soon fatal to creatures accustomed to the pure waters of the ocean. Scott’s cement is said to be better than putty, for fixing in the glass to the columns at the angles.

If cement be used to fix the rock-work of the miniature marine landscape, let it be the best Portland cement, which, when dry, must be soaked by filling the vessel with water, and the water changed several times before the tank will be fit for use.

The best sand for the artificial beach, or bottom, is the Thames’ sand, used by builders; but this must be washed several times, till the water runs off quite clear, before it is fit for use—any other kind of sand, if that cannot be procured, must be submitted to similar washings. Sea-water can be procured by furnishing the steward or captain of any Thames steamer, or the guard of a railway in connection with the coast, with a clean barrel; the charge, in either case, for carriage and trouble, would not exceed two or three shillings.

The artificial salt water has been found sufficient for ZoÖphytes, but not for fish and other of the higher class of marine animals, except for a certain given time.

The composition for artificial sea-water is as follows:—

To these are added four quarts of water, and when the salts are thoroughly dissolved, say on the following day, the liquid must be filtered through a sponge; it is then fit for use.

Care must be taken to observe whether, when the sun shines and the light is bright, the silvery bubbles of oxygen form upon the fronds of the marine vegetation; and if not, it is certain that the marine plants are not in a healthy state, and must be renewed.

Mr. Gosse gives the following final directions as to the class of animals and plants that should be selected in preference for the experiments of beginners.

With regard to sea-weed, he observes, do not take Oar-weeds or Tangle; all the Fuci are of a slimy nature, which it is difficult to manage, and as their size is inconvenient, and they have but little beauty, their absence is not to be regretted.

Of animals, he says, take:—Of Fish—Blennies, Gobies, Wrasses. Of Mollusca—Aplysia, Periwinkle, Chitons, Scallops, and Burrowing Bivalves, such as Venus, Pullastra, &c. Of Crustacea—Eurynome, Portunus puber, Carcinus mÆnas, Ebalia, Corystes, the Paguri, Porcellana platycheles, and the Crangones, the PalÆmones, that is, Shrimps and Prawns. Of Annelids—Pectenaria, the SabellÆ, and the SerpulÆ. Of ZoÖphytes—the Madrepores, and all the ActiniÆ.

Few will establish an Aquarium without deriving great mental improvement, and the enlargement of their circle of acquirement, in a direction highly calculated to develop some of the best and highest feelings of our nature. Even the scientific cannot fail greatly to enlarge their sphere of knowledge in this new, and almost untrodden, field of research. The entomologist, sighing that there are no new TiniÆ to add to his already enormous list, no new Curculios with which to form another volume to the already portly series—these and other physiological Alexanders, weeping for new regions to subdue, may hail the Aquarium as a fertile source of further conquests; for, notwithstanding the numerous and curious discoveries of recent investigators, the depths of the ocean are as yet, comparatively speaking, one of the untrodden fields of science; and a glorious arena it presents—the Aquarium being one of the fairest channels for the detection of its myriads of yet hidden mysteries.

The marine Aquarium is, as yet, a plaything, a mere toy; but it is destined to become a far more important means of advancing science, and ministering to popular instruction, amusement, and wonder, than is yet dreamt of. It has yet to do for the ocean that which our menageries and vast gardens, devoted to the service of natural history, have done for the forests and mountains of the terrestrial portion of our planet.

We shall yet have tropical Aquaria, in which the temperature and qualities of the sea between the tropics will be so successfully imitated, that the glorious shells of those regions will be exhibited in living motion to our greedily-curious gaze; and fish gleaming with unusual dyes—metallic azure, and silvery crimson—will dart and glide in our tropic-tempered tanks, as in their own tropic ocean, for our delight and gratification. We are now entitled to expect from science, that it shall exhibit to us the wonders of the tropic deeps, as it has shown us the glorious plumage and velvet-spotted furs of the denizens of its terrestrial forests.

This is, in fact, the only thing that remains for us to do, in making a fitting popular display of the wonders of Nature, in order that we may surpass the doings of the ancients in that field of popular instruction and gratification.

Even in the days of Cyrus, we learn from the graphic Xenophon and other sources, that every eastern satrap had his “paradises,” in which the most curious animals of distant regions were preserved in a state of liberty, and in a manner suited to their natures, either for the sport of hunting or for the curious gratification of the eye.

The Romans, long before they had attained to the material wealth of the modern nations of Europe, had exhibited to the people of their capital all the noblest animals of Asia and Africa. Even the Giraffe and the Hippopotamus were familiar forms to the Roman populace; while, with the great modern nations of the west, the sight of these wonderful creatures is but quite a recent gratification. It only remained to the ancients to have exhibited a Titanic Aquarium, to render our triumph over their labours in the field of popular natural history impossible. Had but a Roman Warrington or Gosse developed the germ of such an idea, and an Osler existed to furnish the glass—the Pompey, or CÆsar, or Crassus, would not have been wanting to feast the eyes, both of patrician and plebeian Rome, with an Aquarium measuring hundreds of feet in length, in which the monsters of the deep would have been exhibited in deadly conflict, and human divers, armed with net and trident, like the retiariÆ of their gladiatorial combats, would have encountered, beneath the waters, the Shark, the Whale, or the Torpedo, to the shouts of crowded circuses, the centre of which would have been a glass-walled ocean.

But a gigantic Aquarium is, fortunately, a feat that yet remains for modern science to achieve, and which it will doubtless accomplish. The day will arrive when we shall see the living Behemoth—the Titan of the deep—rolling majestic in waves of his native element, perhaps pursued by his cruel enemy the Sword-Fish, or harried by a shoal of Herrings, graphically exemplifying to a London crowd the origin of Yarmouth bloaters. Or we may see the dreaded Shark float round and round the vast glass prison seeking his prey, and the Shark-hunter of the south seas may be imported to exhibit his skill in a bloodless conflict—mocking the attempts of the sea monster to seize him, as the Spanish matador plays long with the infuriated bull; but without necessitating the same catastrophe to the animal, defenceless against the specially-trained skill of his human antagonist. We have already had our crystal palaces, covering their acres, and filled with objects of art and wealth from every quarter of the globe; it is not impossible, therefore, that we may have crystal-walled seas, in which aquatic menageries will form the last new object of fashion and wonder.

For the present, however, the Aquarium is, as I have said, but a toy, yet one full of pleasant instruction; and it doubtless contains the germs of a development, the precise direction of which it is at present difficult to guess.

Plate caption numbering discrepancies have been retained to match the Plate.

List of Plates, ‘pink’ changed to ‘Pink,’ “The Pink Ceramium47”

Page 16, ‘georgeous’ changed to ‘gorgeous,’ “and the gorgeous colours”

Facing page 34 (Plate XII), full stop struck following ‘Plate,’ “Plate XII.”

Page 41, comma inserted after ‘????,’ “Bryon (????), a moss”

Facing page 48 (Plate III), full stop inserted after ‘multifida,’ “Nemaleon multifida.”

Page 59, ‘ZpoÖhytology’ changed to ‘ZoÖphytology,’ “known as ZoÖphytology.”

Page 83, ‘aquainted’ changed to ‘acquainted,’ “all are acquainted with”

Page 89, second ‘the’ struck, “spines of the same”

Page 98, ‘his’ changed to ‘is,’ “he is difficult to”

Page 108, ‘Zoophytes’ changed to ‘ZoÖphytes,’ “Of ZoÖphytes—the Madrepores”