of a cork, or the finger, and that it did not then explode on exposing it to the action of heat, we employed (they say)this means for determining in what state the carbon and azot existed; and we found, that in the fulminating silver, or rather in the fulminating acid, there were two volumes of carbonic acid and one volume of azot, or the same proportion as in cyanogen, or, as it is called by some English chemists, prussine. The whole of the oxide of silver, which seems divided into two portions, one serving as the base of the salt, and the other being an element of the fulminating acid, may be obtained by decomposing the fulminate by hydrochloric acid, and evaporating to dryness. Towards the close of the the operation, a small quantity of nitric acid is added to destroy a small quantity of sal ammoniac, which is formed by the decomposition of an acid, to be hereafter described. Taking the mean of two experiments, fulminating silver contains 77.528 parts in the 100 of oxide of silver; or, silver 72.187, oxygen 5.341.

Having thus ascertained the quantity of oxide in fulminating silver, they then proceeded to determine the other elements. The

fulminate was decomposed by oxide of copper: and the following means were employed to procure the substances perfectly dry, which these chemists describe at length, because it is applicable to any substance, whether animal or vegetable. After mixing the fulminating silver with the oxide of copper, the mixture was introduced into a thick glass tube, about four lines in diameter in the bore, and 13 inches long, a, plate 1; this was connected with a tube, b, containing chloride of calcium, (muriate of lime) which was adapted by means of a flexible leaden pipe, c, to a small receiver placed on the plate, p, of an air-pump. In exhausting the air of the apparatus, the vapour of the water is also carried off, and does not enter the tube containing the mixture, which is dried by the chloride of calcium. But still further to abstract the hygrometic water of the mixture, the tube which contains it is plunged across a cork into a tube of large diameter, de, full of water, which is made to boil; the vapour escapes by the tube, f, and the water which condenses falls into the vessel, g, placed below. By alternately exhausting and filling the apparatus

with air, the substance loses all its hygrometic water. For other substances, which are not decomposed by a temperature above 100°, the tube containing the mixture may be heated in a saline or acid solution, or in an oil bath. The joints of this apparatus may all be made of cork; and when it is of a good quality, the vacuum can be made perfect, without any luting or varnish, except a little paste or fat put into the pores of the cork, if there are any. The mixture of fulminating silver and oxide of copper being decomposed by the action of heat, the gases are collected in an apparatus of the following description, which shows their volume immediately :

Fig. 1, plate 2, ab, is a bell-shaped glass, to which two open rings or handles of cork, one at a and the other at b, are attached, the use of which is to direct the movements of the small graduatedjar, c. The tube, d, to conduct the gas into the graduated jar, has two vertical parallel branches, the ascending part of which almost touches the upper part of the graduated jar, when it is at its lowest position, and the other passes outside of the graduated jar, between the two openings of the cork rings. Fig. 2 represents one of these rings. The vessel ab being filled with mercury, and the ascending branch of the conducting tube being inserted in the graduated jar, this is immersed in the mercury, and the air gradually escapes by the conducting tube. The jar is kept in its new place by means of a cork fixed in a piece of wood, h, sliding along a vertical rod, i, on any part of which it may be fixed at pleasure by the pressure screw, k. The mercury in the graduated jar is brought to the level of the mercury in the lower vessel, and the volume of air in the graduated jar is correctly marked, as well as its temperature. When the mixture is decomposed, the extricated gases force down the mercury in the graduated jar; but by moving the wooden hand along the rod, the mercury is constantly preserved at

its original level, adding mercury at the same time to fill up the space left by the jar rising out of the bath. When the decomposition is completed the fire is removed; and after the apparatus is cooled, the mercury is brought to the same level, both in the jar and in the basin, and the temperature is noted. The volume of air contained in the graduated jar after the operation, less the air it contained before, will be the volume of gas resulting from the decomposition. The water which is produced during the operation by the decomposition of any hydrogenated substance, may be collected by making it pass into a tube containing muriate of lime, placed between the conducting tube and that in which the mixture is placed; but the following is, perhaps, a better method. Take a very small tube, n, Fig. 3, the exterior diameter of which is equal to the interior diameter of the tube, m, containing the mixture, To this a smaller tube, o, filled with chloride of calcium, is attached, to which a cork is adapted, so that it will just enter into the tube, m; its weight is determined, and it is placed in this tube, as seen in Fig. 1; the gases then have no other means of escape but over the chloride in which they deposit their moisture. When the mixture is introduced into the tube, m, care must be taken to leave a space, ms, at the upper part of the tube, that the smaller one may not be thrown out of its place at the moment when the gases are disengaged. To effect the decomposition of the mixture, a small furnace is better than a spirit lamp.

From several experiments made according to this mode, these chemists determined the quantity of cyanogen in 100 parts of fulminating silver to be 17.160, and the whole to be thus composed :—

Art. X.

PHOSPHORUS.

THE thirst for wealth and distinction, so prevalent among men, must, we are inclined to believe, like every thing extensively diffused, have been implanted in us for good. It has, nevertheless, been much stigmatized by those. moralists, who notice only the deviations from the general and regular course of nature. They are men, whose attention is arrested exclusively by what is glaring, like detected crime, or dazzling, like successful ambition; and they record only the hurricane of our passions, forgetting that this is but the momentary interruption of their gentle and perpetual flux and reflux, which, like the trade winds of the tropics, impart health, freshness and vigour to the whole circle of existence. More pleasing, and we will add, more correct, observers, who remark rather the general effects of our passions than the exceptions, say, on the contrary, that the thirst for wealth and distinction is the source of almost every improvement in the condition of

man.

It strengthens the love of liberty, and kindles the spirit of invention. By it the toiling mechanic is kept steady to his task, and the adventurous seaman in

duced to brave all the dangers of the ocean; spreading not only the different products of the globe more equally over every part, but also every where diffusing

*If the reader turns to the Quarterly Journal of Science, No. 33, page 156, he will there find the results stated of some former experiments by Mr. Liebig. They differ so much from these experiments, that we cannot help reverting to them as an additional proof of what we stated at p. 139, viz. that little confidence can be placed in the analysis of the secondary compounds.

knowledge and civilization, so as to bind the whole human race in one general community, having a common interest and a common fate. The alchymists supply an individual example of its beneficial effects in adding to our knowledge. There was no substance, however disgusting, which, in their search after the philosopher's stone, they disdained to examine: and to their intense desire for wealth, we are indebted for a knowledge of the chemical properties of several substances, the repugnance to which is so great, that, but for this powerful motive, men would always have scrupulously avoided them. We have been led to make these observations, by the fact, that phosphorus, the subject of this paper, was discovered in the year 1669 by an alchymist of the name of Brandt, living at Hamburgh, who was endeavouring to procure a liquid from urine capable of converting silver into gold. We are

not sure that the substance was before totally unknown to some adepts: the numerous visions on record; the various tricks, of which the history is preserved, both in the books of modern Europe and in more ancient works, seem to show that the priests of the dark ages and the magi of the east were acquainted with phosphorus, or some equivalent substance. If so, it was afterwards lost, till recovered by the discovery of Brandt. This, though accidental on his part, may be said to have made it known to the scientific world; and the knowledge of it, as long as any use can be made of it, will probably never again be lost. Brandt showed a specimen of the substance he had discovered to Kunkel, a German chemist of some eminence, who mentioned the fact, as a piece of news, to a Mr. Kraft, a friend of his, at Dresden, who immediately repaired to Hamburgh, and purchased the secret from Brandt for 200 dollars, exacting from him, at the same time, a promise not to reveal it to any other person, Kunkel was vexed at the treacherous conduct of Kraft, and

set about discovering phosphorus himself, in which he succeeded, about 1674, though he only knew from Brandt that he obtained it from urine. This, probably, had the effect of preventing Kraft from realizing a fortune by his acquired secret. He came to England, and went to France, exhibiting his phosphorus for this purpose. He says, that he taught the celebrated Boyle the mode of making it; but Boyle, whose authority is much better than that of Kraft, affirmed, that he discovered phosphorus himself, without being previously acquainted with the process. Boyle revealed the mode of making it to his assistant, Godfrey Hankwitz, an apothecary, who for many years supplied all Europe with phosphorus. In 1737, the French government bestowed a reward on a stranger, who appeared at Paris, and communicated a process for making phosphorus. The French chemists, to whom this communication was made, described the process as very tedious; and, soon after, several improvements were made in it. Scheele, the Swedish chemist, discovered a method of obtaining phosphorus from bones, which, though somewhat improved, is the method now generally adopted by those who manufacture phosphorus on a large scale. The chemist may obtain phosphorus as follows:

Let a quantity of bones be burnt, or, as it is termed in chemistry, calcined, till they cease to smoke or to give out any odour, and then reduce them to a fine powder. Put 100 parts of this powder into a bason of porcelain or stone-ware; dilute it with four times its weight of water, and then add, gradually stirring the mixture after every addition, 83 parts of sulphuric acid. The mixture becomes hot, and effervesces; a great number of air bubbles escape. The mixture is left in this state 24 hours, and is stirred every now and then with a glass rod, to make the acid act on the powder. At the end of that time the whole is to be poured on a filter of cloth. The liquid

which runs through the filter is to be received in a porcelain bason, and the white powder which remains on the filter after pure water has been poured over it repeatedly, may be thrown away, as of no use. Pour nitrat of lead, dissolved in water slowly, into this solution, a white powder immediately falls to the bottom, and as long as it continues to fall, nitrat of lead must be added. The whole is then again to be filtered, and the white powder which remains on the filter is to be well washed, allowed to dry, and is then to be mixed with about one sixth of its weight of charcoal powder. Put the mixture into an earthenware retort, and place the retort in a furnace, plunging its beak just under the surface of a vessel with water. The retort is to be gradually heated to whiteness; a vast number of air bubbles issue from its beak, some of which take fire when they reach the surface of the water, and at last there drops out a substance which has the appearance of melted wax, and which congeals under water. This is the simple undecompounded substance, phosphorus. It must be purified by straining it through chamois leather under warm water.

It is of a light amber colour, semi-transparent, though when carefully prepared, it is nearly colourless and transparent. It is as soft as wax, but more cohesive and ductile. It is insoluble in water. Its specific gravity is 1.77. It melts at 99° Fahr., and boils at 550°. When melted, care must be taken to keep it under water, for it is so combustible that it is very likely to take fire. It is soluble in alcohol, ether, and oils, the solutions being transparent. When water is added to the alcohol or ether, the phosphorus separates and burns at the surface of the liquid. If the oily solution be poured on paper, and carried into a dark room, of the temperature of 60°, it shines vividly: at lower temperatures the light is scarcely perceptible. Phosphorus, when taken internally, is poisonous; and it is

related in the Annales de Chimie, that a great number of fowls and turkeys were poisoned by drinking the water in which some newly-made phosphorus had been washed. The blubber-like substances which are found in salt water are known to be phosphorent, and, at the same time, poisonous to poultry, which devours them greedily. Phosphorus has been successfully employed in stopping mortification and curing malignant fevers. Its use in making matches is well known. It is also employed in making phosphoric ether, phosphoric oil, and phosphoric acid.

In the atmosphere, if the temperature be not very low, phosphorus emits a white smoke, having the smell of garlic, which, in the dark, is luminous. The higher the temperature is raised, the more abundant does this smoke become: it results from a combustion of the phosphorus, which is at length entirely consumed. If the air be perfectly dry, the phosphorus does not smoke, because the outside then becomes closely encased with a species of rust, which prevents the action of the atmospherical oxygen. When phosphorus is burnt in oxygen gas, the light and heat are intense; and if the experiment be made in a close vessel, the result of the combustion is found to be what is called phosphoric acid. Phosphorus is never found native, and is entirely the production of art. It is, however, conjectured, as it is an animal product, that the myriads of animalculæ which, as they float in the deep sea, make it like a vast sheet of low and lambent flames, marking every ripple of every wave, every stroke of an oar, and the track of every boat and every ship, with a flash of fire, or a deep and lasting streak of light, produce this effect by the constant emission of phosphorus. The glow-worm and the fire-fly, as well as many other animals, shine by their power of generating and emitting phosphorus. Being scarcely found in any other combination but as it exists in animals, it is regarded as exclusively

an animal product. It has been conjectured also that it is not, and cannot be, a simple substance; and that its elements are contained in some of the substances on which animals subsist. Certainly it has no claim to the character of an element, except that all-paramount one in chemistry, it has never yet been decompounded.

COTTON.

PERHAPS there is no plant, not even the potatoe, on which the prosperity, the comfort, and even the existence of so large a portion of the people of this country now depend, as on cotton. According to Mr. Huskisson's speech in the House of Commons, on Monday, March 8th, 1824, no less than 1,200,000 persons are employed in our country in the cotton manufacture. This number, which does not include the merchant who sends the manufactured article abroad; the seamen who bring home the raw material, and who carry it away when manufactured; the shopkeepers who vend it in the country; nor the persons who make the machines by which it is manufactured,—is about oneseventeenth of our whole population. It is a startling reflection, that this plant is not the produce of our soil, and cannot be cultivated in our climate. The vast number of persons above-mentioned, with all who depend on them, are dependent for the means of subsistence and comfort on a plant cultivated by foreigners, living in climates different from our own. When we reflect on this circumstance, the state of our country strikes us as being very remarkable, and, we had almost said, full of danger. It is, perhaps, even still more remarkable, that a large portion of our people partly subsist on another foreign plant, which can never be naturalized in England. Very nearly 3,000,000 pounds of tea, independent of the quantity smuggled, are annually consumed in Great Britain. And so pleasant and refreshing is this beverage, that we have no