And yet what an opportunity there was for the naturalist, had a single enthusiast arisen? All lands, all climes, and all their natural productions were subservient to the will of the Emperor. The orb of the earth was searched for the roe of eels or the fins of mullets to gratify Caesar. And the whole world might have been explored, and specimens deposited in one gigantic museum in the Eternal City, at the nod of a single individual. But the observer, the lover of Nature, was wanting; and the whole world was ransacked merely to consign its living tenants to the vivaria, and thence to the fatal arena of the amphitheatre. Yet even here the naturalist might have pursued his studies on individuals, and even whole species, both living and dead, without quitting Rome. The animal kingdom lay tributary at his feet, but served only to satiate his appetite or his passions, and not to enrich his mind.
So, again, Rome's armies traversed the globe, and her legions were often explorers of hitherto unknown regions. But no men of science, no corps of savans was attached to her cohorts, to march in the footsteps of conquest and gather the fruits of victory to enrich the schools. Provinces were devastated, great cities plundered, nations made captive, and all the masterpieces of Art borne off to adorn Rome. But Nature was never rifled of her secrets; nor was discovery carried beyond the most material things. The military spirit stifled natural science.
There were then, to be sure, no tendencies of thought to anything but war, pleasure, literature, or art. There was comparatively no knowledge of the physical sciences, whose culture Mr. Buckle has shown to have exerted so powerful an influence on civilization. The convex lens—as since developed into the microscope, the giver of a new world to man—was known to Archimedes only as an instrument to burn the enemy's fleet.
* * * * *
Modern pisciculture in some measure imitates, although, it does not rival the ancient. Many methods have been devised in France and England of breeding and nurturing the salmon, the trout, and other valuable fish, which are annually becoming more scarce in all civilized countries. But all this is on a far different principle from that pursued at Rome. We follow pisciculture from necessity or economy, because fish of certain kinds are yearly dying out, and to produce a cheap food; but the Romans followed it as a luxury, or a childish amusement, alone. And although our aldermen may sigh over a missing Chelonian, as Crassus for his deceased eel, or the first salmon of the season bring a fabulous price in the market, yet the time has long passed when the gratification of appetite is alone thought of in connection with Nature. We know that living creatures are to be studied, as well as eaten; and that the faithful and reverent observation of their idiosyncrasies, lives, and habits is as healthful and pleasing to the mind as the consumption of their flesh is wholesome and grateful to the body. The whole science of Zoölogy has arisen, with its simple classifications and its vast details. The vivaria of the Jardin des Plantes rival those of the Colosseum in magnitude, and excel them in object. Nature is ransacked, explored, and hunted down in every field, only that she may add to the general knowledge. Museums collect and arrange all the types of creative wisdom, from the simple cell to man. Science searches out their extinct species and fossil remains, and tells their age by Geology. The microscope pursues organic matter down into an infinity of smallness, proportionately as far as the telescope traces it upwards in the infinity of illimitable space. Last of all, though not till long after the earth and the air had been seemingly exhausted, the desire of knowledge began to push its way into the arcana of the sea,—that hidden half of Nature, where are to be found those wonders described by Milton at the Creation,—where, in obedience to the Divine command,
"Be fruitful, multiply, and in the seas
And lakes and running streams the waters fill, …
Forthwith the sounds and seas, each creek and bay,
With fry innumerable swarm, and shoals
Of fish, that with their fins and shining scales
Glide under the green wave in sculls that oft
Bank the mid sea: part single or with mate
Graze the sea-weed, their pasture, and through groves
Of coral stray, or sporting with quick glance
Show to the sun their waved coats dropt with gold,
Or in their pearly shells at ease attend
Moist nutriment, or under rocks their food
In jointed armor watch."
But no means were at hand to pursue these unknown creatures to their unknown residences, and to observe their manners when at home. Single, withered, and often mutilated specimens of minute fish, mollusks, or radiata, in the museum, alone illustrated the mysteries of the deep sea. Fish, to be sure, could be kept for longer or shorter periods in globes of glass filled with water; but the more delicate creatures inevitably perished soon after their removal from their mysterious abodes. Such a passionate desire to "search Nature and know her secrets" finally originated the idea of the Aquarium.
The term vivarium was used among the ancients to signify many things,—from the dens of the wild animals which opened under the Colosseum, to an oyster-bed; and so now it may mean any collection of living creatures. Hence it could convey no distinct idea of a marine collection such as we propose to describe. The term aqua was added to express the watery element; but the compound aqua-vivarium was too clumsy for frequent employment, and the abbreviated word aquarium has come into general use.
Thus the real Aquarium is a water-garden and a menagerie combined,—and aims to show life beneath the waters, both animal and vegetable, in all the domestic security of its native home, and in all the beauty, harmony, and nice adaptation of Nature herself. It is no sudden discovery, but the growth of a long and patient research by naturalists.
"What happens, when we put half a dozen gold-fish into a globe? The fishes gulp in water and expel it at the gills. As it passes through the gills, whatever free oxygen the water contains is absorbed, and carbonic acid given off in its place; and in course of time, the free oxygen of the water is exhausted, the water becomes stale, and at last poisonous, from excess of carbonic acid. If the water is not changed, the fishes come to the surface and gulp atmospheric air. But though they naturally breathe air (oxygen) as we do, yet they are formed to extract it from the water; and when compelled to take air from the surface, the gills, or lungs, soon get inflamed, and death at last puts an end to their sufferings.