any

water

quickly invert it in a saucer full of clean cold water, leave it for a short time, and you will gradually find the water rising in the bottle; it dissolves the gas, and the resulting solution is of a pale lemon-colour; chemists call it an aqueous solution of chlorine. If leave you in your bottles, of course it will absorb part of the chlorine, and produce a partial vacuum; the stoppers will become so tightly fixed as to defy all your exertions to remove them: remember, therefore, never to stop the bottles until they are quite full of chlorine. This solution has several remarkable properties: pour a little into a small glass, and then put in a bit of gold leaf-I mean real gold leaf-stir it round and round with a glass rod, the gold dissolves, and thus you obtain an aqueous solution of chloride of gold.

You would never anticipatę such a result with this noble metal, especially if you have ever attempted to dissolve it in nitric, sulphuric, or other strong acids, for none of them have any action on it: but here is water, with a little chlorine in solution, which quickly causes the metal to disappear.

Perhaps you have heard of a solvent for gold, called aqua regia, or nitromuriatic acid, or if not, you can easily make an experiment which will explain its nature.

Put a little nitric acid into one glass, and a little muriatic acid into another; add a bit of gold-leaf to each: the acids separately have no action on it, but now suddenly mix them, and the gold instantly dissolves. You have formed aqua regia or nitro-muriatic acid, in which you find the peculiar odour of chlorine very perceptible; but where has it come from? Why from the muriatic acid, and as follows.

Muriatic acid consists of chlorine, and hydrogen, and nitric acid of oxygen and nitrogen. (pp. 300, 301, vol. i.) When these acids are mixed together, part of the hydrogen of the one unites to part of the oxygen of the other, forming water, and chlorine is liberated in the free state a ready solvent for gold. You recollect that we set out, by evolving chlorine from muriatic acid and oxide of manganese; the theory of the process, you will now easily understand.

Muriatic acid consists of chlorine and hydrogen, oxide of manganese, of oxygen and manganese. (p. 191, vol. ii.) When these are mixed to gether in the retort, part of the hydrogen of the muriatic acid unites with part of the oxygen of the oxide of manganese, forming water, and free chlorine is evolved. So you see it is a very simple case of the decomposition of the acid. There remains in the retort a solution of chloride of manganese. If you put all the black mass on a filter, add a little more water, the chloride of manganese will filter through of a pale pink colour; and by evaporating this solution carefully to dryness on some hot sand, or over a lamp, you will obtain a solid crystalline chloride of manganese.

There are many other methods of obtaining chlorine, especially from common salt, which is a chloride of sodium; but these are rather more complicated, and I do not stop to describe them here. Your readiest source of chlorine is that already detailed.

Now the aqueous solution of chlorine already mentioned has a very singular action on vegetable colours. Vegetable blues are generally rendered red by acids and green by alkalies. But put a bit of litmus-paper

into solution of chlorine, and its blue colour is instantly destroyed: it is regularly bleached. Almost every variety of colour undergoes a similar change. Try various strips of printed calico, and you get illustrations of the art of bleaching.

Dissolve a small lump of indigo in some sulphuric acid, by the aid of a moderate heat, a solution is thus obtained of an intense blue colour, for indigo has the peculiar property of dissolving in sulphuric acid, without reddening or altering colour. Take a drop of this sulphate of indigo, and add it to half a pint of water, so as to dilute the blue a little then pour some of it into the solution of chlorine, and as fast as you pour, the blue colour is bleached, with almost magical velocity. This rapid destruction of a very permanent colour is a fact of vast importance in the arts. A few years since, the art of bleaching was a tardy and uncertain process, dependent chiefly upon the state of the weather; but now, by the introduction of chlorine and its combinations, it is reduced to principles of great perfection and certainty, and enormous quantities of chlorine are daily evolved, and collected in a proper state, for the use of the bleacher.

In the manufacture of chloride of lime for the use of the bleacher, the quantity of chlorine annually evolved, is enormous, and almost surpasses the bounds of belief; indeed, I am almost afraid to state even its daily evolution by one manufacturer, but I had my information from very high authority. "He evolves daily FIFTY TONS' weight of chlorine, and unites it with lime to make the chloride!"

This is an enormous quantity; and a magnificent example of the perfection and precision at which chemistry has arrived.

The bleacher in most instances finds that free gaseous chlorine, or its aqueous solution are not so advantageously applicable to his processes, as chloride of lime. This, therefore, is the form in which chlorine is almost invariably employed, and chloride of lime is now too well known to require any further description here.

If you leave the strips of calico for some time in aqueous solution of chlorine or of chloride of lime, then take them out and dry them: you will find them very white, but very rotten, slitting and dropping into holes upon the slightest touch; because not only has the chlorine destroyed the chemical colour, but also the mechanical texture of the woven fabric.

This is an obvious disadvantage: how is it to be got rid of? Simply by employing a much weaker bleaching-solution, and then well washing the bleached goods in water until all traces of the smell of chlorine disappear. The weak solution will more slowly yet quite as effectually destroy colour, leaving texture unimpaired.

66

Careful manufacturers always attend to this circumstance, but others hurry their processes, and of course the goods are very rotten. Turkey red handkerchiefs," as you very well know, are covered with white spots. Now in the manufacture of these articles, the piece of cotton is first wholly dyed red, and then chlorine is properly applied to those parts intended to be white; they become bleached, and it not unfrequently happens that the goods are hurried into the market retaining chlorine. All the spots and figures are, therefore, very rotten; and if you dry one of these

handkerchiefs before the fire, you can readily poke your finger through all the white spots, because the fibre of the cotton is destroyed.

Paper has its dazzling whiteness conferred upon it by chlorine, and very frequently contains it in notable quantity, especially that paper known as "printing demy." Open a fresh bale of it, and you find the odour of chlorine very perceptible. Of course such paper cannot be very durable.

If you write on it with common ink, in the course of time the writing will fade; because chlorine will readily destroy the colouringmatter of writing-ink. It does not affect that of printing-ink, because that owes its blackness not to iron but to charcoal, which is a singularly unalterable and permanent substance. Blot over a printed page with common ink, and then wash it over with solution of chlorine or chloride of lime, which will remove all the blots, and leave the printing untouched. This fact is obviously of much utility.

Paper thus containing chlorine is often productive of the most serious inconvenience to silversmiths, jewellers, plated button-makers, cutlers, and surgical-instrument-makers, who employ it for wrapping up their polished goods; for although it appears white, and beautiful, and very neat, yet it contains chlorine, a sad enemy to all metal-work; the polished goods soon become tarnished, wholly spoiled, and unsaleable.

Chemistry, of course, gets sadly into disgrace, when its beautiful principles are thus perverted by the mercenary manufacturer.

In addition to the valuable property of destroying colour in the art of bleaching, chlorine and some of its combinations have other important uses. Thus, solution of chlorine or chloride of lime will destroy the unpleasant effluvia arising from decaying animal or vegetable matters. is also of the greatest importance in fumigation, and destroys contagious or infectious matter.

It

People often sprinkle vinegar in sick chambers, or burn perfumes, and call this fumigating; it is of no manner of use save to cover a bad smell; the infectious or contagious matter, if any, remains in full activity, and it can only be effectually destroyed, by fumigation with chlorine or nitric acid vapour, the former may be depended on.

The celebrated Guyton de Morveau invented what he called " Preservative phials." These were strong glass bottles, having ground-glass stoppers, secured by a screw, and containing a mixture for evolving chlorine. Upon entering an infectious atmosphere, the stopper was to be slightly withdrawn, to allow a puff of the gas to escape, and its odour to become perceptible; and according to his experience, this was sufficient to avert the danger of infection.

Fumigation by chlorine is a very simple matter, the mixture for evolving the gas, should be placed in earthen pans on the floor of the room, the windows and doors are to be closed, and things left in this state until the evolution of chlorine ceases; the doors are then to be opened, and the windows also from the outside, letting a current of fresh air sweep into the room until you can enter without inconvenience ; clear out the pans, insert fresh materials, and close up the room as before, until you judge that it is thoroughly fumigated. In fumigating large rooms, of course you must have many pans of the mixture.

Some years ago, a very extensive fumigation of the Milbank Penitentiary was conducted under the direction of Dr. Faraday: and so copious was the evolution of chlorine, that, upon looking through a plate of glass inserted in the door of each long gallery, the whole of its atmosphere appeared intensely yellow.

In such extensive fumigations, the operators are often dreadfully annoyed by the accidental inhalation of the gas; and, indeed, as I have before stated, it is most distressing. The remedy already mentioned may be resorted to, or a sponge soaked in weak liquor ammoniæ, may be folded in a handkerchief, and held close to the mouth, whilst operating; the ammonia or volatile alkali neutralizes the chlorine, and prevents its access to the lungs.

Chlorine is a very heavy gas; compared with hydrogen, its specific gravity is as 36 to 1, and compared with air, as 2.500 to 1.000, so that it may be poured from one vessel to another; in making this experiment, and indeed, all others in which it is concerned, remember to guard against inhaling it.

Chlorine was discovered by the celebrated Scheele, and he called it dephlogisticated muriatic acid, that is, muriatic acid deprived of an imaginary combustible principle called phlogiston. The French chemists called it oxymuriatic acid, imagining it to be muriatic acid containing loosely-combined oxygen.

Sir H. Davy examined it with masterly skill, and found that it contained no oxygen: that it could not be resolved into any simpler form of matter; that it was not a compound but an element, for which he proposed the name of chlorine, as involving no theoretical notions regarding its nature, but simply implying its yellow colour; and should it at any future time be decomposed, and shown to consist of two or more bodies, still the term chlorine will remain unobjectionable. How different is this precision of nomenclature to that of the French school regarding oxygen!

If you imagine Scheele's phlogiston to have been hydrogen, you will at once perceive, how near the true clementary nature of chlorine he had arrived, when he called it dephlogisticated muriatic acid.

Now you still more fully see the absurdity of calling oxygen the universal supporter of combustion, for here is chlorine supporting combustion, with an equal, if not a superior energy; and the absurdity of the term, universal acidifying principle, will become fully apparent hereafter; it is slightly so at present, for chlorine and hydrogen produce muriatic acid.

Such is a slight sketch of some of the most popular properties of chlorine, its evolution, its power of supporting combustion, of destroyin colour, and contagious or infectious matter. All these the chemi well acquainted with, but of the ultimate nature of this singular stance he knows nothing.

296

THE MATHEMATICAL MISCELLANY. No. I.

CONDUCTED BY PROFESSOR GILL, FLUSHING INSTITUTE, LONG ISLAND. NEW YORK, 1836.

Ir can never be an object of indifference to Englishmen, to witness the efforts made for the extension of science by their Transatlantic brethren. Those efforts have been in every sense gigantic: but especially in all that relates to the arts of life and civilization. Still, till very recently, America fell far behind ourselves in those fundamental branches of science which must form the real basis of every solid scientific structure,— the mathematical. Prior to the publication of Dr. Bowditch's translation of Laplace, and the excellent notes appended to it, the American press could not boast of one single mathematical work comparable to hundreds published in the mother-country. The cause is easily explained, and has been pointed out over and over again by American writers,—the slavish prejudice which prevails, amidst all the personal vanity of the Americans, that nothing can be produced in America at all comparable to the works published in London. In the arts of life they felt themselves free, and less shackled by fiscal imposts than the parent-country, and there they put forth all their strength; but in pure science, as well as in literature, they have fallen as far below us as in commercial and manufacturing efforts they have surpassed us. We are not sure, however, that the American publishers do not find it more to their advantage to keep up this delusion, than to use any effort to dispel it: inasmuch as they thus avoid the expense of purchasing "copy," but find it made ready to their hands in the form of printed books imported from London! No English work of eminence, and adapted to the taste or wants of their own population, issues from the press in this country, which is not, as if by magic, circulated throughout America, and from a dozen American presses simultaneously, in less than three months after the most favoured “ town reader" has perused it! Happy the publisher who gets a single week the start of his competitors! He makes half a fortune in that single week,—provided the book is one calculated to have a 66 good run."

Though we are ready to admit that much of the literature, as well as of the science of America, is inferior in every point to our own, yet it must be obvious that this does not arise from want of good models,—for all that we have, they have too. It arises from the discouragement of American effort, and from this alone. Our advantage may possibly be found in this; but it certainly is not intentionally consulted. American patriotism would dictate a different course; and it is improbable that after the splendid efforts of Washington Irving, Webster, and Cooper, in literature, and of Bowditch in mathematical physics, that great country will look so coldly on the labours of her own children. It is her interest to foster the genius of her own soil; and she cannot be much longer blinded to it.

It is well known to every well-read mathematician, that in this country pure science was cultivated in comparative silence and obscurity, by means of certain periodical works more or less exclusively devoted to them (and especially the Ladies' and Gentlemen's Diaries) whilst in our