THE MARINE AQUARIUM. MR. GOSSE'S ACCOUNT OF HIS EXPERIMENTS.

MANY persons who have seen the aquarium at the Zoological Gardens, Regent's Park, will be greatly interested in the following remarks. Moreover, thousands of persons are setting up, and will continue to set up, not only marine, but fresh water aquariums. And, therefore, everything which contributes to a proper knowledge of the management of them must be highly acceptable. Mr. Gosse says:—

If we attempt to collect and to keep marine animals alone in sea-water, however pure it may have been at first, it speedily becomes offensively fetid, the creatures look sickly, and rapidly die off, and we are glad to throw away the whole mass of corruption.

Why is this?-why should they die in our vessels when they live so healthily in the little pools and basins of the rock, that are no larger? For the very same reason that we should quickly die in a room perfectly air-tight. The blood of all animals requires to be perpetually renewed by the addition to it of the element called oxygen; and when it cannot obtain this it becomes unfit for the support of life. Terrestrial animals obtain this gaseous element from the air; aquatic animals (that is, those which are strictly such) obtain it from the water. But in either case it is principally produced by living plants while under the action of light. If, then, we can furnish our captives with a perpetual manufactory of oxygen, the main cause of their sudden death is removed. Of course they have other requirements, but this is the most urgent, the indispensable.

In a state of nature, the rocks, the crannies, the pools, the sea-bottom are studded with various living plants, which we call sea-weeds; and these, under the daily stimulus of sunlight, direct or indirect, produce and throw off a vast quantity of oxygen, which, by the action of the waves and currents, is diffused through all parts of the habitable sea, and maintains the health of its countless swarms of animals.

In an aquarium we seek to imitate this chemistry of nature. We collect the plants as well as the animals; and, a little observation teaching us how to proportion the one to the other, we succeed in maintaining, on a small scale, the balance of animal and vegetable life. Other less important benefits result from this arrangement; the creatures love retirement and shelter, and this they find in the umbrageous fronds; they delight to roam, and to play, and to rest in the feathery tufts, and not a few find their favourite food in the delicate leaves of the herbs.

On the other hand, the plant is indebted to the animal for some of its supplies. The carbon, with which its solid parts are built up, is derived from the carbonic acid which is thrown off by animals in the process of breathing; a poisonous gas which would soon vitiate the water, were it not taken up and appropriated by the plants.

Such, then, is the principle on which the aquarium is founded; and any conditions under which it can be carried out will serve, provided of course they be suitable in other respects to the habits of the animals and our purpose in keeping them. I have at present at my residence at Islington one marine tank full of animals and plants in the highest condition, the water in which, though as clear as crystal and quite colourless, has never been even removed from the vessel since it was first put in, 19 months ago. I have, also, other tanks and vases, which are respectively 17, 14, 13, and 4 months old. The successful establishment of these has not been achieved without some failures and losses, which yet must not be considered as unmitigated misfortunes, since they have added to my experience, and better fitted me to understand and sympathise with the difficulties of other beginners.-Handbook to the Marine Aquarian.

DISEASES OF THE TEETH. AT a recent meeting of the Western Medical Society of London, Mr. Thomas C. White read a paper on the cause of

After

dental caries (carious teeth). entering upon various physiological and pathological considerations, the author expressed his belief in the hereditary influence, and cited some curious in stances. Certain trades tend to produce caries, of which grocers and lucifermatch makers were examples. Certain localities, especially damp ones, and those where imperfect drainage existed, appear to be amongst the causes; and, also, mechanical violence.

Of the teeth most likely to be affected the first molars appeared to occupy the highest place, and those of the upper jaw usually were the first to decay. The "wisdom teeth" were often evolved in an unsound state. The popular idea of the contagion of caries was met by asserting, that the apparently successive decay of adjoining teeth was due to the pressure of the teeth against each other, caused by the upward and forward growth of them. For if such teeth were examined at an early period, long before caries had manifested itself, a round chalky spot might be noticed, caused by the crumbling of the enamel fibres beneath the firm, but steady, pressure exerted upon them: this opens the dentine to attacks of acid, and other irritants; and sphacelus is the result.

Having thus discussed many and various causes of dental caries, and contrasted the frequency of the disease in civilised society with the immunity enjoyed by man in his savage state, as well as that of the lower animals, the author was impelled to the conclusion, that "it may in great measure be attributed to the artificial mode of living in a civilized state, which brings on a morbid condition of the fluids, resulting in impaired nutrition.

The treatment must, of course, vary with the states and circumstances of the disease. In an incipient state, from pressure, the removal of the affected enamel, and polishing the surface was recommended. Where, on the contrary, the disease has proceeded so far as to excavate the substance, the sooner it is cleaned out and stopped with gold or amalgam, the better. (See Enquire Within, 142.) When the caries has

progressed to such an extent that the dentine is soft and yielding, the slightest pressure causing intense pain, stopping is inapplicable, and recourse must be had to escharotics. Of these, perhaps, the most efficient was a combination of oxide of arsenic with acetate of morphia, mixed into a paste, with creosote. This gives slight pain for about two hours, after which it ceases, and the tooth can then be stopped and made serviceable for some time. The practice of indiscriminate extraction was declared to be unwarrantable.

SOAP-A GOSSIP OVER THE

WASH-TUB.

SOAP at the present day being very extensively adulterated, and the public generally being so little disposed to apply their reason to the subject, suggests to me, that in your first Interview with your readers you would allow me to communicate the following facts:-Soap, as you are aware, is a detergent article, applied to all cleansing purposes, consequently that soap must be most economical which contains and retains the greatest proportion of the detergent property. Soap is manufactured from oil or fat, either vegetable or animal. That soap is most durable and detergent, which is manufactured from animal fat. Palm oil and cocoa-nut oil are largely used in producing a soap which the public are always seeking, viz., a low priced one. Cocoa-nut oil soap is useful for marine purposes, being used in cold water; but if used in warm or hot water it wastes quickly, and although containing an excess of the detergent material, the nature of the grease does not allow the necessary rubbing on the articles to be cleansed, consequently the soap becomes wasted in the water, making strong suds, and thereby making the suds exceedingly caustic and injurious to the hands of those who wash. Palm oil soap is also subject to like wasteful consumption (but not to the extent of the cocoa-nut oil soap.) If employed in hot water, it being a vegetable grease it will allow only a moderate rubbing on the article to

cleansed, giving a large quantity of lather. Persons generally suppose the lather gives the cleansing property, which is not the case. To cleanse thoroughly, the soap should be solid enough to resist the friction of rubbing, yielding the detergent property on the part to be cleansed. Soap manufactured from palm oil is very extensively adulterated. It will absorb when in a liquid state one-third of a chemical mixture commonly used in that class of soap, and yet have the appearance of ordinary soap. Aside from these soaps, I state, that taking the bulk of soap manufactured, two-thirds of which is adulterated, more or less, in neighbourhoods where the inhabitants are poor, which class of persons so commonly seek out low priced articles-take such districts as New Cut, Whitechapel, Whitecross-street, Bethnal-green, and neighbourhoods of the kind where the poor locate, the greatest quantities of the low-priced soap is sold, the shopkeeper, knowing how much this adulterated soap wastes even in keeping, buys only a few days' supply, and retails it out as fresh as possible on receiving it from the soap makers. In some of the lower priced palm soap one half is adulteration. So inferior is this article that the soap maker, who prepares it, is obliged to adopt a drying room, similar to drying of bricks made from clay: this soap is piled in a room heated with hot air (to dry, or, more correctly, to bake the surface) of each cake; this process of drying is intended to shut in the excess of moisture, and the portion of silica used in the adulteration gives a hard surface. Immediately when dried it is despatched to the shopkeeper, thence sold at the supposed cheap price, the poor being most generally the purchasers, being tempted by the colour and cheapness. The fanciful idea of having yellow soap a pale colour has given much opportunity to carry on this adulteration. Twenty-five years ago a sound genuine detergent soap was the article in common use: it was of a brown or yellow colour, properly called yellow soap. At the present day "Primrose," "Extra Pale," "XXX

Pale," and terms of the like are given The public study the pleasing of the eye first, and will not buy a brown or yellow soap, be it ever so genuine, in consequence of its colour. This class of soap is almost certain to contain the durable and cleansing quality (if made by good makers). Common soap is so inferior in its cleansing property that a large quantity of the crystal of soda is used, as the soap is found not to perform the detergent process.

To go back to the year, say 1830, crystal soda was scarcely in use for laundry purposes, but it will be found that so large is the use of this article at the present time that something like 20,000 tons reach the metropolis yearly. But such is the practice of adulteration that this article, soda, is adulterated to the extent of one half in some localities; the component ingredients are seriously injurious; viz., sulphuric acid being one of the chief elements in the manufacture of this so-called soda: the consequence is, that whenever it is used, the fabric becomes injured and rotten from the effect of this acid, and the hands of washerwomen suffer.

I omitted to notice that common hot ai dried palm soap is very extensively mar ufactured in our large towns.

The article called fancy soap must not be passed by, although generally bought by persons capable of judging in part; but when we find "honeysuckle soap," "turtle soap," with an endless variety of fine names, it is not out of place to ask what is it which gives these shades of colour. My answer is, the colourman furnishes the vermilion, the umber, the damp blue, and mineral colours of this poisonous nature. Fancy soap can be obtained of a much more pure and suitable character; but if the public will not accept truths, and prefer following after fanciful articles, they must bear with the inconvenience resulting from such indifference. conclude, avoid low priced soap: the better sorts will be found most economical; the linen washed thereby will last longer. And remember that coloured soaps, though attractive to the eye, are generally injurious to the skin.

To

INFLUENCE OF THE MOON

UPON HUMAN HEALTH. DR. MEAD details a number of facts that have come under his own, as well as the observation of his contemporaries, demonstrative of lunar influence. Dr.

Mead was physician to St. Thomas's Hospital during the time of Queen Anne's wars with France; and whilst occupying this honourable position great

numbers of wounded sailors were

brought into the hospital. He observed

that the moon's influence was visible on most of the cases then under his care. He cites a case, communicated to him

by Dr. Pitcairne, of a patient, thirty years of age, who was subject to epistaxis, whose affection returned every year in March and September-that is, of the new moon-near the vernal and autumnal equinoxes. Dr. Pitcairne's own case is referred to as a remarkable

fact corroborative of lunar influence.

In the month of February, 1687, whilst at a country seat near Edinburgh, he was seized, at nine in the morning, the very hour of the new moon, with a violent hæmorrhage from the nose, accompanied with severe syncope. On the following day, on his return to town, he found that the barometer was lower at that very hour than either he or his friend Dr. Gregory, who kept the journal of the weather, had ever observed it; and that another friend of his, Mr. Cockburn, professor of philosophy, had died suddenly, at the same hour, from hæmorrhage from the lungs; and also that six of his patients were seized, at the same time, with various kinds of hæmorrhages, all arising, it was supposed, from the effect of lunar influence on the condition of the barometer. Dr. Mead's opinions are formed upon some ingenious and probable hypotheses respecting the influence of the moon upon the atmosphere, and of the atmosphere upon human beings. Similar views were entertained by Dr. Francis Balfour, who had for many months the charge of a regiment of Sepoys, of Cooch Behar, immediately under the vast range of mountains which separate the north

ern part of Bengal from Bootan. The prevalent diseases were fevers, or "fluxes" attended with fevers. During the month four hundred men were invalided.

The greater part, however, of these cases were convalescent in the course of eight days that intervened bebut during the remaining months of tween the full and change of the moon; his stay in that district, the diseases most double their extent at every full previously mentioned increased to alagain to their former standard during and change of the moon, falling down the eight days which intervened between these two periods. With regard four expresses himself as perfectly sato small-pox occurring in India, Dr. Baltisfied that the full and change of the increased the accompanying fever to a moon interferred with the eruption, and dangerous degree. The opinion of both these physicians have been decreed worthy of quotation by Dr. Forbes Winslow, in his papers upon medical juris

prudence.

How To MAKE MONEY.-Let the business of everybody else alone, and attend to your own: don't buy what you don't want, use every hour to advantage, and study to make even leisure hours useful: think twice before you throw away a shilling; remember you will have another to make for it: find recreation in looking after your business, and so your business will not be neglected in looking after recreation: buy low; sell fair, and take care of the profits: look over your books regularly, and if you find an error, trace it out: should a stroke of misfortune come upon you in trade, retrench, work harder; but never fly the track :" confront difficulties with unflinching perseverance, and they will disappear at last; though you should even fail in the struggle you will be honoured; but shrink from the task, and you will be despised. By following these rules, however, you never need say "fail;" pay debts promptly, and so exact your dues: keep your word.