Chapter XI: The Confessional (1)

The reader, if a person of any common knowledge of human nature, will easily see the direction in which a young, inexperienced, and impressible girl would naturally be tending under all the influences which we perceive to have come upon her.

But in the religious faith which Agnes professed there was a modifying force, whose power both for good and evil can scarcely be estimated.

The simple Apostolic direction, "Confess your faults one to another," and the very natural need of personal pastoral guidance and assistance to a soul in its heavenward journey, had in common with many other religious ideas been forced by the volcanic fervor of the Italian nature into a certain exaggerated proposition. Instead of brotherly confession one to another, or the pastoral sympathy of a fatherly elder, the religious mind of the day was instructed in an awful mysterious sacrament of confession, which gave to some human being a divine right to unlock the most secret chambers of the soul, to scrutinize and direct its most veiled and intimate thoughts, and, standing in God's stead, to direct the current of its most sensitive and most mysterious emotions.

Every young aspirant for perfection in the religious life had to commence by an unreserved surrender of the whole being in blind faith at the feet of some such spiritual director, all whose questions must be answered, and all whose injunctions obeyed, as from God himself. Thenceforward was to be no soul-privacy, no retirement, nothing too sacred to be expressed, too delicate to be handled and analyzed. In reading the lives of those ethereally made and moulded women who have come down to our day canonized as saints in the Roman Catholic communion, one too frequently gets the impression of most regal natures, gifted with all the most divine elements of humanity, but subjected to a constant unnatural pressure from the ceaseless scrutiny and ungenial pertinacity of some inferior and uncomprehending person invested with the authority of a Spiritual Director.

That there are advantages attending this species of intimate direction, when wisely and skilfully managed, cannot be doubted. Grovelling and imperfect natures have often thus been lifted up and carried in the arms of superior wisdom and purity. The confession administered by a Fenelon or a Francis de Sales was doubtless a beautiful and most invigorating ordinance; but the difficulty in its actual working is the rarity of such superior natures,--the fact, that the most ignorant and most incapable may be invested with precisely the same authority as the most intelligent and skilful.

He to whom the faith of Agnes obliged her to lay open her whole soul, who had a right with probing-knife and lancet to dissect out all the finest nerves and fibres of her womanly nature, was a man who had been through all the wild and desolating experiences incident to a dissipated and irregular life in those turbulent days.

It is true, that he was now with most stringent and earnest solemnity striving to bring every thought and passion into captivity to the spirit of his sacred vows; but still, when a man has once lost that unconscious soul-purity which exists in a mind unscathed by the fires of passion, no after-tears can weep it back again. No penance, no prayer, no anguish of remorse can give back the simplicity of a soul that has never been stained.

If Padre Francesco had not failed to make those inquiries into the character of Agnes's mysterious lover which he assumed to be necessary as a matter of pastoral faithfulness.

It was not difficult for one possessing the secrets of the confessional to learn the real character of any person in the neighborhood, and it was with a kind of bitter satisfaction which rather surprised himself that the father learned enough ill of the cavalier to justify his using every possible measure to prevent his forming any acquaintance with Agnes. He was captain of a band of brigands, and, of course, in array against the State; he was excommunicated, and, of course, an enemy of the Church. What but the vilest designs could be attributed to such a man? Was he not a wolf prowling round the green, secluded pastures where as yet the Lord's lamb had been folded in unconscious innocence?

Father Francesco, when he next met Agnes at the confessional, put such questions as drew from her the whole account of all that had passed between her and the stranger. The recital on Agnes's part was perfectly translucent and pure, for she had said no word and had had no thought that brought the slightest stain upon her soul. Love and prayer had been the prevailing habit of her life, and in promising to love and pray she had had no worldly or earthly thought. The language of gallantry, or even of sincere passion, had never reached her ear; but it had always been as natural to her to love every human being as for a plant with tendrils to throw them round the next plant, and therefore she entertained the gentle guest who had lately found room in her heart without a question or a scruple.

As Agnes related her childlike story of unconscious faith and love, her listener felt himself strangely and bitterly agitated. It was a vision of ignorant purity and unconsciousness rising before him, airy and glowing as a child's soap-bubble, which one touch might annihilate; but he felt a strange remorseful tenderness, a yearning admiration, at its unsubstantial purity. There is something pleading and pitiful in the simplicity of perfect ignorance,--a rare and delicate beauty in its freshness, like the morning-glory cup, which, once withered by the heat, no second morning can restore. Agnes had imparted to her confessor, by a mysterious sympathy, something like the morning freshness of her own soul; she had redeemed the idea of womanhood from gross associations, and set before him a fair ideal of all that female tenderness and purity may teach to man. Her prayers--well he believed in them,--but be set his teeth with a strange spasm of inward passion,--when he thought of her prayers and love being given to another. He tried to persuade himself that this was only the fervor of pastoral zeal against a vile robber who had seized the fairest lamb of the sheepfold; but there was an intensely bitter, miserable feeling connected with it, that scorched and burned his higher aspirations like a stream of lava running among fresh leaves and flowers.

The conflict of his soul communicated a severity of earnestness to his voice and manner which made Agnes tremble, as he put one probing question after another, designed to awaken some consciousness of sin in her soul. Still, though troubled and distressed by his apparent disapprobation, her answers came always clear, honest, unfaltering, like those of one who _could_ not form an idea of evil.

When the confession was over, he came out of his recess to speak with Agnes a few words face to face. His eyes had a wild and haggard earnestness, and a vivid hectic flush on either cheek told how extreme was his emotion. Agnes lifted her eyes to his with an innocent wondering trouble and an appealing confidence that for a moment wholly unnerved him. He felt a wild impulse to clasp her in his arms; and for a moment it seemed to him he would sacrifice heaven and brave hell, if he could for one moment hold her to his heart, and say that he loved her,--her, the purest, fairest, sweetest revelation of God's love that had ever shone on his soul,--her, the only star, the only flower, the only dew-drop of a burning, barren, weary life. It seemed to him that it was not the longing, gross passion, but the outcry of his whole nature for something noble, sweet, and divine.

But he turned suddenly away with a sort of groan, and, folding his robe over his face, seemed engaged in earnest prayer. Agnes looked at him awe-struck and breathless.

"Oh, my father!" she faltered, "what have I done?"

"Nothing, my poor child," said the father, suddenly turning toward her with recovered calmness and dignity; "but I behold in thee a fair lamb whom the roaring lion is seeking to devour. Know, my daughter, that I have made inquiries concerning this man of whom you speak, and find that he is an outlaw and a robber and a heretic,--a vile wretch stained by crimes that have justly drawn down upon him the sentence of excommunication from our Holy Father the Pope."

Agnes grew deadly pale at this announcement.

"Can it be possible?" she gasped. "Alas! what dreadful temptations have driven him to such sins?"

"Daughter, beware how you think too lightly of them, or suffer his good looks and flattering words to blind you to their horror. You must from your heart detest him as a vile enemy."

"Must I, my father?"

"Indeed you must."

"But if the dear Lord loved us and died for us when we were his enemies, may we not pity and pray for unbelievers? Oh, say, my dear father, is it not allowed to us to pray for all sinners, even the vilest?"

"I do not say that you may not, my daughter," said the monk, too conscientious to resist the force of this direct appeal; "but, daughter," he added, with an energy that alarmed Agnes, "you must watch your heart; you must not suffer your interest to become a worldly love: remember that you are chosen to be the espoused of Christ alone."

While the monk was speaking thus, Agnes fixed on him her eyes with an innocent mixture of surprise and perplexity,--which gradually deepened into a strong gravity of gaze, as if she were looking through him, through all visible things into some far-off depth of mysterious knowledge.

"My Lord will keep me," she said; "my soul is safe in His heart as a little bird in its nest; but while I love Him, I cannot help loving everybody whom He loves, even His enemies: and, father, my heart prays within me for this poor sinner, whether I will or no; something within me continually intercedes for him."

"Oh, Agnes! Agnes! blessed child, pray for me also," said the monk, with a sudden burst of emotion which perfectly confounded his disciple. He hid his face with his hands.

"My blessed father!" said Agnes, "how could I deem that holiness like yours had any need of my prayers?"

"Child! child! you know nothing of me. I am a miserable sinner, tempted of devils, in danger of damnation."

Agnes stood appalled at this sudden burst, so different from the rigid and restrained severity of tone in which the greater part of the conversation had been conducted. She stood silent and troubled; while he, whom she had always regarded with such awful veneration, seemed shaken by some internal whirlwind of emotion whose nature she could not comprehend.

At length Father Francesco raised his head, and recovered his wonted calm severity of expression.

"My daughter," he said, "little do the innocent lambs of the flock know of the dangers and conflicts through which the shepherds must pass who keep the Lord's fold. We have the labors of angels laid upon us, and we are but men. Often we stumble, often we faint, and Satan takes advantage of our weakness. I cannot confer with you now as I would; but, my child, listen to my directions. Shun this young man; let nothing ever lead you to listen to another word from him; you must not even look at him, should you meet, but turn away your head and repeat a prayer. I do not forbid you to practise the holy work of intercession for his soul, but it must be on these conditions.

"My father," said Agnes, "you may rely on my obedience"; and, kneeling, she kissed his hand.

He drew it suddenly away, with a gesture of pain and displeasure.

"Pardon a sinful child this liberty," said Agnes.

"You know not what you do," said the father, hastily. "Go, my daughter,--go, at once; I will confer with you some other time"; and hastily raising his hand in an attitude of benediction, he turned and went into the confessional.

"Wretch! hypocrite! whited sepulchre!" he said to himself,--"to warn this innocent child against a sin that is all the while burning in my own bosom! Yes, I do love her,--I do! I, that warn her against earthly love, I would plunge into hell itself to win hers! And yet, when I know that the care of her soul is only a temptation and a snare to me, I cannot, will not give her up! No, I cannot!--no, I will not! Why should I _not_ love her? Is she not pure as Mary herself? Ah, blessed is he whom such a woman leads! And I--I--have condemned myself to the society of swinish, ignorant, stupid monks,--I must know no such divine souls, no such sweet communion! Help me, blessed Mary!--help a miserable sinner!"

Agnes left the confessional perplexed and sorrowful. The pale, proud, serious face of the cavalier seemed to look at her imploringly, and she thought of him now with the pathetic interest we give to something noble and great exposed to some fatal danger. "Could the sacrifice of my whole life," she thought, "rescue this noble soul from perdition, then I shall not have lived in vain. I am a poor little girl; nobody knows whether I live or die. He is a strong and powerful man, and many must stand or fall with him. Blessed be the Lord that gives to his lowly ones a power to work in secret places! How blessed should I be to meet him in Paradise, all splendid as I saw him in my dream! Oh, that would be worth living for,--worth dying for!"

* * * * *

THE AQUARIUM.

The sumptuous abode of Licinius Crassus echoes with his sighs and groans. His children and slaves respect his profound sorrow, and leave him with intelligent affection to solitude,--that friend of great grief, so grateful to the afflicted soul, because tears can flow unwitnessed. Alas! the favorite sea-eel of Crassus is dead, and it is uncertain whether Crassus can survive it!

This sensitive Roman caused his beloved fish to be buried with great magnificence: he raised a monument to its memory, and never ceased to mourn for it. So say Macrobius and Aelian.

This man, we are told, who displayed so little tenderness towards his servants, had an extraordinary weakness concerning his fine sea-eels. He passed his life beside the superb fish-pond, where he lovingly fattened them from his own hand. Nor was his fondness for pisciculture exceptional in his times. The fish-pond, to raise and breed the finest varieties of fish, was as necessary an adjunct to a complete establishment as a barn-yard or hen-coop to a modern farmer or rural gentleman. Wherever there was a well-appointed Roman villa, it contained a _piscina_; while many gardens near the sea could boast also a _vivarium_, which, in this connection, means an oyster-bed.

Fish-ponds, of course, varied with the wealth, the ingenuity, and the taste of their owners. Many were of vast size and of heterogeneous contents. The costly _Muraena_, the carp, the turbot, and many other varieties, sported at will in the great inclosures prepared for them. The greater part of the Roman emperors were very fond of sea-eels. The greedy Vitellius, growing tired of this dish, would at last, as Suetonius assures us, eat only the soft roe; and numerous vessels ploughed the seas in order to obtain it for him. The family of Licinius took their surname of Muraena from these fish, in order thus to perpetuate their silly affection for them. The love of fish became a real mania, and the _Murcena Helena_ was worshipped.

Hortensius, who possessed three splendid country-seats, constructed in the grounds of his villa at Bauli a fish-tank so massive that it has endured to the present day, and so vast as to gain for it even then the name of _Piscina Mircihilis_. It is a subterraneous edifice, vaulted, and divided by four rows of arcades and numerous columns,--some ten feet deep, and of very great extent. Here the largest fishes could be fattened at will; and even the mighty sturgeon, prince of good-cheer, might find ample accommodations.

Lucullus, that most ostentatious of patricians, and autocrat of _bons-vivants_, had a mountain cut through in the neighborhood of Naples, so as to open a canal, and bring up the sea and its fishes to the centre of the gardens of his sumptuous villa. So Cicero well names him one of the Tritons of fish-pools. His country-seat of Pausilypum resembled a village rather than a villa, and, if of less extent, was more magnificent in luxury than the gigantic villa of Hadrian, near Tivoli. Great masses of stone-work are still visible, glimmering under the blue water, where the marble walls repelled the waves, and ran out in long arcades and corridors far into the sea. Inlets and creeks, which wear even now an artificial air, mark the site of _piscinae_ and refreshing lakes. Here were courts, baths, porticoes, and terraces, in the _villa urbana_, or residence of the lord,--the _villa rustica_ for the steward and slaves,--the _gallinarium_ for hens,--the _apiarium_ for bees,--the _suile_ for swine,--the _villa fructuaria_, including the buildings for storing corn, wine, oil, and fruits,--the _horius_, or garden,--and the park, containing the fish-pond and the _vivarium_. Statues, groves, and fountains, pleasure-boats, baths, jesters, and even a small theatre, served to vary the amusements of the lovely grounds and of the tempting sea.

But it was not to be supposed that men satiated with the brutal shows of the amphitheatre, even if enervated by their frequentation of the Suburra, could, on leaving the city, be always content with simple pleasures, rural occupations, or pleasure-sails. Habit demanded something more exciting; and the ready tragedy of a fish-pond filled with ravenous eels fed upon human flesh furnished the needed excitement. For men _blasé_ with the spectacles of lions and tigers lacerating the _bestiarii_. It was much more exciting to witness a swarm of sea-eels tearing to pieces an awkward or rebellious slave. Vedius Pollio, a Roman knight of the highest distinction, could find nothing better to do for his dear Muraenae than to throw them slaves alive; and he never failed to have sea-eels served to him after their odious repast, says Tertullian. It is true, these wretched creatures generally deserved this terrible punishment; for instance, Seneca speaks of one who had the awkwardness to break a crystal vase while waiting at supper on the irascible Pollio.

Pisciculture was carried so far that fish-ponds were constructed on the roofs of houses. More practical persons conducted a stream of river-water through their dining-rooms, so that the fish swam under the table, and it "was only necessary to stoop and pick them out the moment before eating them; and as they were often cooked on the table, their perfect freshness was thus insured. Martial (Lib. X., Epigram. XXX., vv. 16-25) alludes to this custom, as well as to the culture and taming of fish in the _piscina_.

"Nec seta largo quaerit in mari praedam,
Sed e cubiclo lectuloque jactatam
Spectatus alte lineam trahit piscis.
Si quando Nereus sentit Aeoli regnum,
Ridet procellas tula de suo mensa.
Piscina rhombum pascit et lupos vernas,
Nomenculator mugilem citat notum
Et adesse jussi prodeunt senes mulli."

It having been remarked that the red mullet passed through many changes of color in dying, like the dolphin, fashion decreed that it should die upon the table. Served alive, inclosed in a glass vessel, it was cooked in the presence of the attentive guests, by a slow fire, in order that they might gloat upon its sufferings and expiring hues, before satisfying their appetites with its flesh.

It will not surprise us to learn that the eminent _gourmand_ Apicius offered a prize to the inventor of a new sauce made of mullets' livers.

But we may remark, that fish, like all other natural objects, were studied by the ancients only to pet or to eat. All their views of Nature were essentially selfish; none were disinterested, reverential, deductive, or scientific. Nature ministered only to their appetites, in her various kinds of food,--to their service, in her beasts of burden,--or to their childish or ferocious amusement, with talking birds, as the starling, with pet fish, or with pugnacious wild beasts. There was no higher thought. The Greeks, though fond of flowers, and employing them for a multitude of adornments and festive occasions entirely unequalled now, yet did not advance to their botanical study or classification. The Roman, if enamored of the fine arts, could see no Art in Nature. There was no experiment, no discovery, and but little observation. The whole science of Natural History, which has assumed such magnitude and influence in our times, was then almost entirely neglected.

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.

"Now, if a fish-globe be not overcrowded with fishes, we have only to throw in a goodly handful of some water-weed,--such as the _Callitriche_, for instance,--and a new set of chemical operations commences at once, and it becomes unnecessary to change the water. The reason of this is easily explained. Plants absorb oxygen as animals do; but they also absorb carbonic acid, and from the carbonic add thus absorbed they remove the pure carbon, and convert it into vegetable tissue, giving out the free oxygen either to the water or the air, as the case may be. Hence, in a vessel containing water-plants in a state of healthy growth, the plants exhale more oxygen than they absorb, and thus replace that which the fishes require for maintaining healthy respiration. Any one who will observe the plants in an aquarium, when the sun shines through the tank, will see the leaves studded with bright beads, some of them sending up continuous streams of minute bubbles. These beads and bubbles are pure oxygen, which the plants distil from the water itself, in order to obtain its hydrogen, and from carbonic acid, in order to obtain its carbon."[A]

[Footnote A:_The Book of the Aquarium_, by Sidney Hibbert.]

Thus the water, if the due proportion of its animal and vegetable tenants be observed, need never be changed. This is the true Aquarium, which aims to imitate the balance of Nature. By this balance the whole organic world is kept living and healthy. For animals are dependent upon the vegetable kingdom not only for all their food, but also for the purification of the air, which they all breathe, either in the atmosphere or in the water. The divine simplicity of this stupendous scheme may well challenge our admiration. Each living thing, animal or plant, uses what the other rejects, and gives back to the air what the other needs. The balance must be perfect, or all life would expire, and vanish from the earth.

This is the balance which we imitate in the Aquarium. It is the whole law of life, the whole scheme of Nature, the whole equilibrium of our organic world, inclosed in a bottle.

For the rapid evolution of oxygen by plants the action of sunlight is required. That evolution becomes very feeble, or ceases entirely, in the darkness of the night. Some authorities assert even that carbonic acid is given off during the latter period. So, too, they claim that there are two distinct processes carried on by the leaves of plants,--namely, respiration and digestion: that the first is analogous to the same process in animals; and that by it oxygen is absorbed from, and carbonic acid returned to the atmosphere, though to a limited degree: and that digestion consists in _the decomposition of carbonic acid by the green tissues of the leaves under the stimulus of the light, the fixation of solid carbon, and the evolution of pure oxygen_. The theory of distinct respiration has been somewhat doubted by the highest botanical authority of this country; but the theory of digestion is indisputable. And it is no less certain that all forms of vegetation give to the air much more free oxygen than they take from it, and much less carbonic acid, as their carbonaceous composition shows. If fresh leaves are placed in a bell-glass containing air charged with seven or eight per cent. of carbonic acid, and exposed to the light of the sun, it will be found that a large proportion of the carbonic acid will have disappeared, and will be replaced by pure oxygen. But this change will not be effected in the dark, nor by any degree of artificial light. Under water the oxygen evolved from healthy vegetation can be readily collected as it rises, as has been repeatedly proved.

Why carbonic acid is, to a limited degree, given off by the plant in the night, is merely because the vital process, or the fixation of carbon and evolution of oxygen, ceases when the light is withdrawn. The plant is only in a passive state. Ordinary chemical forces resume their sway, and the oxygen of the air combines with the newly deposited carbon to reproduce a little carbonic acid. But this must be placed to the account of decomposing, not of growing vegetation; for by so much as plants grow, they decompose carbonic acid and give its oxygen to the air, or, in other words, purify the air.

It has been found by experiment, that every six pounds of carbon in existing plants has withdrawn twenty-two pounds of carbonic acid gas from the atmosphere, and replaced it with sixteen pounds of oxygen gas, occupying the same bulk. And when we consider the amount of carbon that is contained in the tissues of living, and of extinct vegetation also, in the form of peat and coal, we may have some idea of the vast body of oxygen which the vegetable kingdom has added to the atmosphere.

And it is also to be considered, that this is the only means we know of whereby free oxygen is given to supply the quantity constantly consumed in respiration, combustion, and other vast and endless oxygen-using processes. It follows, therefore, that animals are dependent upon plants for their pure oxygen, as well as for their food. But the vegetable kingdom might exist independently of the animal; since plants may derive enough carbon from the soil, enriched by the decaying members of their own race.

There is, however, one exception to the law that plants increase the amount of oxygen in the air. During flowering and fruiting, the stores of carbon laid up in the plant are used to support the process, and, combining with the oxygen of the air, both carbonic acid and heat are given off. This has been frequently proved. In large tropical plants, where an immense number of blossoms are crowded together, the temperature has risen twenty to fifty degrees above that of the surrounding air.

As most of the aquatic plants are cryptogamous, or producing by spores, and not by flowers, it seems probable that the evolution of carbonic acid and heat is much less in degree in them, and therefore less in the water than in the air. We may, therefore, venture to lay it down as a general principle, that plants evolve free oxygen in water, when in the sunlight, and remove the carbonic acid added to the water by the respiration of the animals.

But since this is a digestive or nutritive process, it follows that aquatic plants may derive much or all of their food from the water itself, or the carbon in it, in the same manner as the so-called air-plant, which grows without soil, does from the air. It is true, at any rate, that, in the fresh-water aquarium, the river and brook plants need no soil but pebbles; and that the marine plants have no proper root, but are attached by a sort of sucker or foot-stalk to stones and masses of rock. It is very easy to see, then, how the aquarium may be made entirely self-supporting; and that, excepting for the larger carnivorous fish, who exhaust in a longer or shorter period the minute creatures on which they live, no external food is required.

A very simple experiment will prove the theory and practicability of the aquarium. In a glass jar of moderate size was placed a piece of _Ulva latissima_, or Sea-Lettuce, a broad-leaved, green, aquatic plant, and a small fish. The mouth was closed by a ground glass stopper. The jar was exposed to the light daily; the water was never changed; nor was the glass stopper removed, excepting to feed the fish, once or twice a week, with small fragments of meat. At the end of eight months both remained flourishing: the fish was lively and active; and the plant had more than half filled the bottle with fresh green leaves.

Any vessel that will hold water can, of course, be readily converted into an aquarium. But as we desire a clear view of the contents at all times, glass is the best material. And since glass globes refract the light irregularly and magnify and distort whatever is within them, we shall find an advantage in having the sides of the aquarium parallel and the form rectangular. As the weight of the aquarium, when filled with water, is enormous,--far more than we should at first imagine,--it follows that it must be capable of resisting pressure both from above and from within. The floor and stand, the frame and joints must be strong and compact, and the walls of plate or thick crown glass. The bottom should be of slate; and if it is designed to attach arches of rock-work inside to the ends, they, too, must be of slate, as cement will not stick to glass. The frame should be iron, zinc, or well-turned wood; the joints closed with white-lead putty; the front and back of glass. There is one objection to having the side which faces the light of transparent glass, and that is that it transmits too much glare of sunlight for the health of the animals. In Nature's aquarium the light enters only from above; and the fish and delicate creatures have always, even then, the shady fronds of aquatic plants or the shelter of the rocks,--as well as the power of seeking greater depths of water, where the light is less,--to protect themselves from too intense a sunshine. It is, therefore, sometimes advisable to have the window side of the aquarium made of glass stained of a green color. It is desirable that all aquarial tanks should have a movable glass cover to protect them from dust, impure gases, and smoke.

When we speak of an aquarium, we mean a vessel holding from eight to thirty gallons of water. Mr. Gosse describes his larger tank as being two feet long by eighteen inches wide and eighteen inches deep, and holding some twenty gallons. Smaller and very pretty tanks may be made fifteen inches long by twelve inches wide and twelve deep. Great varieties in form and elegance may be adapted to various situations.

There are two kinds of aquaria, the fresh- and the salt-water: the one fitted for the plants and animals of ponds and rivers; the other for the less known tenants of the sea. They are best described as the River and the Marine Aquarium, and they differ somewhat from each other. We shall speak first of the fresh-water aquarium.

The tank being prepared, and well-seasoned, by being kept several weeks alternately full and empty, and exposed to the sun and air, so that all paint, oil, varnish, tannin, etc., may be wholly removed, the next thing is to arrange the bottom and to plant it. Some rough fragments of rock, free from iron or other metals that stain the water, may be built into an arch with cement, or piled up in any shape to suit the fancy. The bottom should be composed entirely of shingle or small pebbles, well washed. Common silver sand, washed until the water can be poured through it quite clear, is also suitable.

Mould, or soil adapted to ordinary vegetation, is not necessary to the aquatic plants, and is, moreover, worse than useless; since it necessitates the frequent changing of the water for some time, in order to get rid of the soluble vegetable matter, and promotes the growth of Confervae, and other low forms of vegetation, which are obnoxious.

Aquatic plants of all kinds have been found to root freely and flourish in pebbles alone, if their roots be covered. The plants should be carefully cleared of all dead parts; the roots attached to a small stone, or laid on the bottom and covered with a layer of pebbles and sand.

The bottom being planted, the water may be introduced through a watering-pot, or poured against the side of the tank, so as to avoid any violent agitation of the bottom. The water should be pure and bright. River-water is best; spring-water will do, but must be softened by the plants for some days before the fishes are put in.

Sunshine is good for the tank at all seasons of the year. The fresh- requires more than the salt-water aquarium. The amount of oxygen given off by the plants, and hence their growth and the sprightliness of the fishes, are very much increased while the sun is shining on them.

In selecting plants for the aquarium some regard is to be paid to the amount of oxygen they will evolve, and to their hardiness, as well as to their beauty. When it is desired to introduce the fishes without waiting long for the plants to get settled and to have given off a good supply of oxygen, there is no plant more useful than the _Callitricke_, or Brook Star-wort. It is necessary to get a good supply, and pick off the green heads, with four or six inches only of stem; wash them clean, and throw them into the tank, without planting. They spread over the surface, forming a rich green ceiling, grow freely, and last for months. They are continually throwing out new roots and shoots, and create abundance of oxygen. Whenever desired, they can be got rid of by simply lifting them out.

The _Vallisneria_, or Tape-Grass, common in all our ponds, is essential to every fresh-water tank. It must be grown as a bottom-plant, and flourishes only when rooted. The _Nitella_ is another pleasing variety. The _Ranunculus aquatilis_, or Water-Crowfoot, is to be found in almost every pond in bloom by the middle of May, and continues so into the autumn. It is of the buttercup family, and may be known as a white buttercup with a yellow centre. The floating leaves are fleshy; the lower ones finely cut. It must be very carefully washed, and planted from a good joint, allowing length enough of stem to reach the surface. Some of the blossom-heads may also be sprinkled over the surface, where they will live and bloom all through the summer. The _Hydrocharis_, or Frog's-Bit, and the _Alisma_, or Water-Plantain, are also easily obtained, hardy and useful, as well as pleasing. Many rarer and more showy varieties may be cultivated; we have given only the most common and essential. All the varieties of _Chara_ are interesting to the microscopist, as showing the phenomenon of the circulation of the sap, or Cyclosis.

Of the living tenants of the aquarium, those most interesting, as well as of the highest organization, are the fishes. And among fishes, the family of the _Cyprinidae_ are the best adapted to our purpose; for we must select those which are both hardy and tamable. _Cyprinus gibelio_, the Prussian Carp, is one of the best. It will survive, even if the water should accidentally become almost exhausted of oxygen. It may be taught, also, to feed from the hand. None of the carp are very carnivorous. _Cyprinus auratus_, or the Gold-fish, is one of the most ornamental objects in an aquarium. But the Minnow, _C. phoxinus_, is the jolliest little fish in the tank. He is the life of the collection, and will survive the severest trials of heat and cold. The Chub, a common tenant of our ponds, is also a good subject for domestication. The Tench and Loach are very interesting, but also very delicate. Among the spiny-finned fishes, the Sticklebacks are the prettiest, but so savage that they often occasion much mischief. For a vessel containing twelve gallons the following selection of live stock is among those recommended: Three Gold Carp, three Prussian Carp, two Perch, four large Loach, a dozen Minnows, six Bleak, and two dozen Planorbis. Some varieties of the Water-Beetles, or Water-Spiders, which the fishes do not eat, may also well be added. The Newt, too, is attractive and harmless.

All may go on well, and the water remain clear; but after the tank has been established several weeks, the inner sides of the glass will show a green tinge, which soon increases and interferes with the view. This is owing to the growth of a minute confervoid vegetation, which must be kept down. For this purpose the Snail is the natural remedy, being the ready scavenger of all such nuisances. Snails cling to the sides, and clean away and consume all this vegetable growth. The _Lymnea_ is among the most efficient, but unfortunately is destructive, by eating holes in the young fronds of the larger plants, and thus injuring their appearance. To this objection some other varieties of snail are not open. The _Paludina_ and _Planorbis_ are the only kinds which are trustworthy. The former is a handsome snail, with a bronze-tinted, globular shell; the latter has a spiral form. These will readily reduce the vegetation. And to preserve the crystal clearness of the water, some Mussels may be allowed to burrow in the sand, where they will perform the office of animated filters. They strain off matters held in suspension in the water, by means of their siphons and ciliated gills. With these precautions, a well-balanced tank will long retain all the pristine purity of Nature.

Specimens for the river aquarium may be readily obtained in almost any brook or pool, by means of the hand-net or dredge. It will be astonishing to see the variety of objects brought up by a successful haul. Small fish, newts, tadpoles, mollusks, water-beetles, worms, spiders, and spawn of all kinds will be visible to the naked eye; while the microscope will bring out thousands more of the most beautiful objects.

A very different style of appearance and of objects distinguishes the Salt-water or Marine Aquarium.

As the greater part of the most curious live stock of the salt-water aquarium live upon or near the bottom, so the marine tank should be more shallow, and allow an uninterrupted view from above. Marine creatures are more delicately constituted than fresh-water ones; and they demand more care, patience, and oversight to render the marine aquarium successful.

Sea-sand and pebbles, washed clean, form the best bottom for the salt-water aquarium. It must be recollected that many of the marine tenants are burrowers, and require a bottom adapted to their habits. Some rock-work is considered essential to afford a grateful shelter and concealment to such creatures as are timid by nature, and require a spot in which to hide: this is true of many fishes. Branches of coral, bedded in cement, may be introduced, and form beautiful and natural objects, on which plants will climb and droop gracefully.

Sea-water dipped from the open sea, away from the mouths of rivers, is, of course, the best for the marine aquarium. If pure, it will bear transportation and loss of time before being put into the tank. It may, however, not always be possible to get sea-water, particularly for the aquarium remote from the seaboard, and it is therefore fortunate that artificial sea-water will answer every purpose.

The composition of natural sea-water is, in a thousand parts, approximately, as follows: Water, 964 parts; Common Salt, 27; Chloride of Magnesium, 3.6; Chloride of Potassium, 0.7; Sulphate of Magnesia, (Epsom Salts,) 2; Sulphate of Lime, 1.4; Bromide of Magnesium, Carbonate of Lime, etc., .02 to .03 parts. Now the Bromide of Magnesium, and Sulphate and Carbonate of Lime, occur in such small quantities, that they can be safely omitted in making artificial seawater; and besides, river and spring water always contain a considerable proportion of lime. Therefore, according to Mr. Gosse, we may use the following formula: In every hundred parts of the solid ingredients, Common Salt, 81 parts; Epsom Salts, 7 parts; Chloride of Magnesium, 10 parts; Chloride of Potassium, 2 parts; and of Water about 2900 parts, although this must be accurately determined by the specific gravity. The mixture had better be allowed to stand several days before filling the tank; for thus the impurities of the chemicals will settle, and the clear liquor can be decanted off. The specific gravity should then be tested with the hydrometer, and may safely range from 1026 to 1028,--fresh water being 1000. If a quart or two of real sea-water can be obtained, it is a very useful addition to the mixture. It may now be introduced into the tank through a filter. But no living creatures must be introduced until the artificial water has been softened and prepared by the growth of the marine plants in it for several weeks. Thus, too, it will be oxygenated, and ready for the oxygen-using tenants.

It is a singular fact, that water which has been thus prepared, with only four ingredients, will, after being a month or more in the aquarium, acquire the other constituents which are normally present in minute quantities in the natural sea-water. It must derive them from the action of the plants or animals, or both. Bromine may come from sponges, or sea-wrack, perhaps. Thus artificial water eventually rights itself.

The tank, having been prepared and seasoned with the same precaution used for the river aquarium, and having a clear bottom and a supply of good water, is now ready for planting. Many beautifully colored and delicately fringed Algae and Sea-Wracks will be found on the rocks at low tide, and will sadly tempt the enthusiast to consign their delicate hues to the aquarium. All such temptations must be resisted. Green is the only color well adapted for healthy and oxygenating growth in the new tank. A small selection of the purple or red varieties may perhaps be introduced and successfully cultivated at a later day, but they are very delicate; while the olives and browns are pretty sure to die and corrupt the water. It must be remembered, too, that the Algae are cryptogamous, and bear no visible flowers to delight the eye or fancy. Of all marine plants, the _Ulva latissima_, or Sea-Lettuce, is first and best. It has broad, light-green fronds, and is hardy and a rapid grower, and hence a good giver of oxygen. Next to this in looks and usefulness comes the _Enteromorpha compressa_, a delicate, grass-like Alga. After a while the _Chondrus crispus_, or common Carrageen Moss, may be chosen and added. These ought to be enough for some months, as it is not safe to add too many at once. Then the green weeds _Codium tomentosum_ and _Cladophora_ may be tried; and, still later, the beautiful _Bryopsis plumosa_. But it is much better to be content with a few Ulvae, and others of that class, to begin with; for a half dozen of these will support quite a variety of animal life.

After a few hardy plants are well set, and thriving for a week or two, and the water is clear and bubbly with oxygen, it will be time to look about for the live stock of the marine aquarium. Fishes, though most attractive, must be put in last; for as they are of the highest vitality, so they require the most oxygen and food, and hence should not be trusted until everything in the tank is well a-going.

The first tenants should be the hardy varieties of the Sea-Anemones, or _Actiniae_,--which are Polyps, of the class Radiata. The _Actinia mesembryanthemum_ is the common smooth anemone, abounding on the coast, and often to be found attached to stones on the beach. "When closed," says Mr. Hibbert, "it has much resemblance to a ripe strawberry, being of a deep chocolate color, dotted with small yellow spots. When expanded, a circle of bright blue beads or tubercles is seen within the central opening; and a number of coral-like fingers or tentacles unfold from the centre, and spread out on all sides." It remains expanded for many days together, if the water be kept pure; and, having little desire for locomotion, stays, generally, about where it is placed. It is a carnivorous creature, and seeks its food with its ever-searching tentacles, thus drawing in fishes and mollusks, but, most frequently, the minute Infusoria. Like other polyps, it may be cut in two, and each part becomes a new creature. It is a very pretty and hardy object in the aquarium. There are many varieties, some of which are very delicate, as the _Actinia anguicoma_, or Snaky-locked Anemone, and the pink and brown _Actinia bellis_, which so resembles a daisy. Others, as the _Actinia parasitica_, are obtainable only by deep-sea dredging; "and, as its name implies, it usually inhabits the shell of some defunct mollusk. And more curious still, in the same shell we usually find a pretty crab, who acts as porter to the anemone. He drags the shell about with him like a palanquin, on which sits enthroned a very bloated, but gayly-dressed potentate, destitute of power to move it for himself."[B]

[Footnote B: Hibbert's _Book of the Aquarium_.]

The _Actinia gemmacea_, or Gemmed Anemone, the _Actinia crassicornis_, and the Plumose Anemone are all beautiful, but tender varieties.

The Anemones require but little care; they do not generally need feeding, though the Daisy and Plumose Anemone greedily take minced mutton, or oyster. But, as a rule, there are enough Infusoria for their subsistence; and it is safer not to feed them, as any fragments not consumed will decay, and contaminate the water.

Next in order of usefulness, hardiness, and adaptability to the new aquarium, come the Mollusks. And of these, Snails and Periwinkles claim our respectful attention, as the most faithful, patient, and necessary scavengers of the confervoid growths, which soon obscure the marine aquarium.