Of course, the more simple and fewer the Resolutions are, the easier they will be comprehended and the more readily assented to. Should the Resolutions be adopted, the Society will be formed; if not, a second meeting may take place; or it may be impossible to reconcile the different views of the persons desirous of forming such a Society, and thus" impossible to constitute it. There can be little fear, however, of this, if each person comes to the meeting with a disposition candidly to listen to what others may say, and without too great a confidence in his own ideas of what will best promote the success of the Society.

of an evening, and it being only of an evening that the Members of the Society propose to meet, or can meet, he must of course be precluded, however unwillingly, from taking any active or directing part in its proceedings. At the same time, it seems to him, he has now received so many communications on the subject, that there is such a number of persons willing to unite and form the proposed Society as would secure its permanent suc cess. Sixteen gentlemen, several of them having sent their real addresses, have signified to him their wish to join the Society. This number, with the advantages of fered by W.J. and Luzitanus, is ample for beginning; and nothing more seems necessary than that they should meet. A. M. proposes that the meeting should take place on Saturday, the 19th inst., which is quite impossible, because the Editor has no other means of communicating with several persons who wish to join the Society, but "The Chemist," which does not appear till that day. He would suggest, therefore, that the meeting should take place on Saturday, the 26th, at eight o'clock in the evening, at the room offered by W. J., and should any thing occur to make it inconvenient or impossible to meet on that day, he will announce it in his publication of the 26th.*

Till the gentlemen who wish to form such a Society meet, it is quite impossible to prescribe any further rules for their proceedings, which may not do more harm than good. The object of the Society would be to prosecute in common the study of chemistry; and some individuals, possessing large means and leisure, might desire to expend more money and time in the pursuit than was compatible with the views of others. Thus, it will be observed, that there is at starting a considerable difference of opinion among those who wish to join the Society as to the sum to be paid; and all the advice we' shall at present give our young friends is, to fix the subscription at the sum most suitable to the majority who attend the Meeting and both those who desire to expend more, and those who do not wish to expend so much, may either fall into the general view, or each party may endeavour form a Society by itself, As the Editor cannot take any part in the proceedings of such a Society, he' must, like A. M., express his unwillingness to give it a particular direction, when it would be impossible for him to guide it to its ainr. Without being personally acquainted with the parties, it would be presumptuous to give them advice. He always meant to limit his deavours in favour of the Society to bringing those together who wish ***

At the first meeting, probably the best mode of proceeding would be, immediately to elect a Chairman and Secretary for the night, – for the former is indispensable to preserve order, even among a very small number of persons; and without the latter there can be no record of the proceedings. A series of Resolutions should then be proposed, embracing the principle of forming such a Society, the number of persons it is to consist of, the amount of the subscriptions of each, the times of meeting, and the mode of proceeding to be adopted at each meeting.

to

to establish it. . That, he trusts, is now in a fair way of being accomplished; and he is quite sure, the individual who first suggested forming it, and the other individuals who have entered with so much zeal into his plan, will so temper their ardour with discretion, as to conduct it, without that experience on which A. M. is pleased to compliment him, to a happy issue.

TO EXTRACT GELATINE FROM BONES.

A By M. Darcet. "AFTER the bones have been submitted to ebullition for some hours to remove the fat, they are to be properly treated with weak hydrochloric acid, (dilute muriatic acid) which dissolves the whole of the phosphate and carbonate of lime, as well as the phosphate of magnesia, and leaves naked the pure gelatine, preserving the form of the bones, and as flexible as a rush.

"To remove from the substance thus obtained, the small portions of fat and acid which it may contain, it is exposed to a stream of cold water, which gives it white ness and a semi-transparency. After having well wiped it with linen, it is put into baskets, and plunged for a few moments in boiling water, and afterwards in cold water again. If, notwithstanding all these precautions, the gelatine still retains any acidity, it may be put into a solution of sub-carbonate of soda, which saturates the acid by forming hydrochlorate of soda, which is easily removed by two or three washings, and indeed the presence of this salt can be productive of no inconvenience. When the gela

previously steeped in cold water for five or six hours; in swelling up, it absorbs 58 per cent. of its own weight of the cold water. By putting two parts and a half of gelatine in 100 parts of boiling water, the liquor forms a jelly on cooling, without the necessity of prolonging the ebullition, By evaporation this jelly may be made thick enough to be cut out in tablets, which are dried and préserved like the raw gelatine. The latter is the most convenient in laying in a large stock of provisions; but the other is more convenient for daily use, because it dissolves more speedily.

"Under these two forms the gelatine is imputrescible, and may be kept without alteration or loss, as if it was still in the bones, where it is known to be in a great measure preserved from decomposition.

"Used as glue by joiners, &c. gelatine has a tenacity one half greater than the best Paris glue, It furnishes the manufacturers of painted papers, and painters in distemper, with a tremulous glue, perfectly colourless and less expensive than what they formerly used, Hats prepared with this substance do not become cockled or blistered by rain, a defect of all hats that are prepared with Flanders glue,

"Gelatine serves also for preparing lip-glue of the first quality, transparent leaves for tracing drawings, and sheets of factitious horn. M. Darcet has had an idea of making transparent wafers with it for sealing letters. He has manufactured some paper by grinding raw gelatine as rags, are pounded, and operating with this gelatine1 reduced into a paste, as they do in paper-mills with common paper o By rolling or laminating the paper thus obtained, a kind of parchment is produced, which may be very useful.

66

Gelatine is likewise made to enter into the composition of sulphurous water-baths, to prevent then from having that irritating action on the skin generally complained of by patients."

VANIC AND ELECTRO-MAGNETIC EXPERIMENTS. (From the Philosophical Magazine.) SEVEN hundred feet of copper wire, nearly as thick as a knittingneedle, were made to encircle the columns of the lecture-room. One end of the wire was connected with one end of a large calorimotor, the other terminated in a cup of mercury; into this, a wire proceeding from the other pole of the calorimotor was introduced. Under these circumstances, a magnetic needle placed near the middle of the circuit was powerfully affected; and when the circuit was first interrupted, and then re-established by removing the wire from the cup, and introducing it again, the influence appeared to reach the needle as quickly as if the circuit had not exceeded seven inches in extent. The needle being allowed to become stationary in the meridian, while the circuit was interrupted, and the end of the wire being then returned into the mercury, the deviation of the needle and the contact of the wire with the metal appeared perfectly simultaneous.

A wire was made to circulate with great rapidity, by means of two wheels, about which it passed like a band. The wheels being metallic, and severally connected with the different poles of a calorimotor, it was found that the motion neither accelerated nor retard

ed the galvanic influence; and it made no difference whether the needle was placed near the portion of the wire which moved from the positive pole to the negative, or the portion which moved in the opposite direction.

If a jet of mercury, in communication with one pole of a very large calorimotor, is made to fall on the poles of a horse-shoe magnet communicating with the other, the metallic stream will be curved outwards or inwards, accordingly as one or the other side of the magnet may be exposed to the jet, or as the pole communicating with the mercury may be positive or negative. When the jet of mercury is made to fall just within the interstice, formed by a series of horse-shoe

usual way, the stream will be bent in the direction of the interstice, and inwards or outwards, accordingly as the sides of the magnet or the communication with the galvanic poles may be exchanged. This result is analogous to those obtained by Messrs. Barlow and Marsh with wires or wheels.

It is well known that a galvanic pair, which will, on immersion in an acid, intensely ignite a wire connecting the zinc and copper surfaces, will cease to do so after the acid has acted on the pair for some moments, and that ignition cannot be reproduced by the same apparatus without a temporary removal from the exciting fluid.

I have ascertained that this recovery of igniting power does not take place if, during the removal from the acid, the galvanic surfaces be surrounded either by hydrogen gas, nitric oxide gas, or carbonic acid gas. When surrounded by chlorine, or by oxygen gas, the surfaces regain their igniting power in nearly the same time as when exposed to the air.

The magnetic needle is, nevertheless, much more powerfully affected by the galvanic circuit, when the plates have been allowed to repose, whether it take place in the air or in any of the gases abovementioned.

TO CORRESPONDENTS.

Both the notes of A. D. and H. R. W. have been received. If the matter of the communications promised by the former be good, we shall not reject them on account of the language. The letter of H. R.W. will be inserted.

J.L., who requests us not to publish his letter, will see by our former Number, that we were ready to do him jus tice as soon as we learnt the circumstance to which he alludes.

R. C. and J. Clark, with reference to the Chemical Society, have both been received.

Communications (post paid) to be addressed to the Editor at the Publishers'.

London: Published by KNIGHT and LA

CEY, 55, Paternoster-row.-Printed by
B. Bensley, Bolt-court, Fleet-street.

MR. TIGERE'S

STOVE AND
APPARATUS.

THE contrivance of this gentleman, of which the following is a description, will be found convenient for heating sand-pots and other chemical operations.

A A is a German-stove, the body of which is made, in the usual manner, of plate iron; but with its grate, B, made moveable, so as to be raised or lowered, and retained at any required height. This is effected by means of the iron stem, C, affixed to the grate in its centre, and passing through a guide-hole, D, in the cross-bar EE, which is secured to the legs of the stove. Holes are made in the stem C; and an iron pin, F, being put through any one of them, and resting upon the cross bar EE, the grate is supported at the height required; and, on withdrawing the pin, the grate, and the fuel upon it, is lowered, and the heat instantly abated in consequence.

GHI is an improved support for a receiver, &c.; it being capable of the nicest adjustment in height, as well as sideways, by means of the screwed stem, G, which acts in a female screw, H, firmly affixed upon the table or stand, I, and passes through a hole, J, made in the table to receive it. The upper end of the screw H is made cyiindrical; and is received into a cylindrical hole, made in the piece of wood, K, affixed underneath the square wooden box, L. The cylindrical head of the screw has a groove or channel made around it, to receive a pin, which is affixed in the piece K, so as to prevent it from coming off the cylindrical head, and yet allow it to play around it. A hole is also made through the screw, near its head K, through which to pass a pin or lever to turn it by, so as to elevate or depress the box L, and adjust it to the greatest accuracy; and far more conveniently than can be done by the use of wooden blocks of various heights or thicknesses, and as generally recommended in chemical works.

This box, L, has an opening made in its side, to receive one of the two necks of the receiver, N, into which the beak of the retort, O, is fitted by grinding; and into its other neck the short tube, P, is fitted. This tube has one arm of the double-curved tube, Q, fitted upon it, by grinding; and its other arm is received into an upright tube, R, which passes through, and is secured in a perforation made in a thick cap of glass, S, which may be either ground to fit air-tight upon the top of the large receiver, T, or be cemented upon it. U is a safety-tube, of a peculiar shape; which is also ground air-tight into an aperture made to receive it, in the glass cap, S. This safety-tube may be four feet or more in length, as recommended by Dr. W. Lewis, in his article "On assaying gold," and it has its upper end, V, bent at a right-angle, and loosely stopped with a smali cork, so as to readily open, in case of any undue pressure being exerted within the receiver, T. W is a kind of bag, or cistern, made of a piece of oil-skin, sewed together at its edges, and securely bound around the outside of the glass cap, S. Its use is, to hold water, to cool the gaseous matters distilled over, previous to their entering the large receiver, T; as well as to prevent the loosening of the cement by the heat, when the glass cap, S, is so secured to the top of that receiver. The bag, W, is supported by four strings affixed to the rim of it, and affixed to a nail, &c, above it; and the safety-tube, U, is also to be secured above, in

a proper manner.

The whole, apparatus described was used by its inventor for various chemical operations, and particularly for making the chiorate of potash, of which he could prepare two pounds per day, by charging the retort with the usual materials for generating chlorine,