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with a new, certain, and easy Method of obtaining those alkalis perfectly pure. By M. DARTIGUES, &c. &c.—The writer of this paper first shews that M. Paisse could only obtain carbo. nate of barytes by decomposing nitrate of barytes with carbo, nate of potash, and that he has confounded this substance with the pure or caustic barytes which may be obtained by exposing nitrate of barytes to a strong heat.-He afterward recommends the following process as the most economical way of procuring pure barytes:-- the carbonate of this earth, natural or arti. ficial, is to be strongly heated with 12 or 15 times its weight of charcoal ; after whịch, the residuum is to be well washed, and will then be found as pure as that which is obtained when the nitrate has been decomposed by heat.

Note on the Properties of the Oxalic Acid. By M. DARRACO M. Brugnatelli having stated, in the 29th volume of the Che. mical Annals, that oxalic acid has erroneously been considered as a proper re-agent to detect the presence of lime ; and having supported this assertion by some experiments; the author of the present note was induced to repeat them, and, from the results which he obtained, he is of opinion that these conclusions are not accurate : since oxalic acid always precipitates lime from various solutions, except the acid menstrua be in excess. In such cases, therefore, this excess should be saturated by an alkali, and oxalate of ammonia should be employed in preference to uncombined oxalic acid.

A new Process for the Earthing (Terrage) of Sugar, proposed by M. Hapel. Lachenaie, of Guadaloupe.- This paper cannot be abridged, nor does it contain any thing interesting to the generality of chemical readers.

Observations on the internal Temperature of Vegetables, compared with that of the Atmosphere. By M. SOLOMÉ.-We are here presented with an account of some experiments, made by introducing thermometers into holes bored in the trunks of certain trees. The author observes that the only value, which he attaches to these first attempts, is the having opened the way to philosophers who may be better qualified to make such experiments, and will render them useful. M. SOLOMÉ, however, mistakes in supposing that he is the first who has entered into this investigation; because the late Mr. John Hunter, so long since as the winter of 1775-6, made a great number of experiments on the internal temperature of vegetables, exactly in the manner adopted by M. SOLOMÉ ; and an account of the whole may be seen in the Phil. Trans. for 1778, p. 7.

The real or affected ignorance of the French, respecting the state of science in this country, is truly astonishing !!!

An

An Essay on the Preparution of Phosphoric ther. By M. BOUDET.-Having prepared some pure plosphoric acid, by decomposing nitric acid with phosphorus, M. BOUDET mixed it with alcohol, and distilled with a Woulfe's apparatus. He obtained, ist. an acid liquor slightly coloured, which had a disagreeable odour ; 2dly. a very pale yellowish oil, which swam on the former liquor.-On examination, he found the first product to be alcohol, but the second possessed the characters of phosphoric æther.

Notice, concerning Oxide of Iron. By M. ROARD.—The experiments made by this chemist were intended to ascertain the best and most economical method of removing iron-moulds from linen, &c.—The acidulous oxalate of pot-ash (salt of sorrel) has been commonly employed for this purpose, and M. ROARD compared its effects with the acidulous tartrite of potash (cream of tartar) and with very dilute sulphuric acid. Having stated the results of his comparative experiments, he says; • In consequence of the different trials to which I have subjected the substances capable of acting on oxide of iron and on ink, we see that acidulous oxalate of pot-ash does not exclusively possess this property; since the acidulous tartrite of pot-ash, and very dilute sulphuric acid, may be employed for the same purpose with very considerable advantages, not only on a large scale, but also in every other case in which the oxalate of pot-ash has hitherto been used.'

Memoir on the Gum contained in the Bulb of the Hyacinthus non Scriptus. By M. LEROUX.-In our account of the 39th vol. of these annals, we noticed a letter from M. Deyeux to the edi. tors, giving an account of this discovery of M. LEROUX.-In the present paper, this gentleman first describes the various processes by which the gum may be extracted : but, as this is essentially performed by pounding the root, by infusing the pulp in water, by occasionally subjecting it to pressure, and by evaporation, we need not enter into minute particulars. He then states the proportion of the principles of the hyacinth, recently taken out of the earth, to be nearly as follows.

Water-73,1

Gum-18,
Vegetable fibre-71

100,0

The memoir is concluded by some remarks on the culture of the plant, and the utility of the gum.

Experiments concerning the Analysis and Synthesis of the Alkalis and Earths, announced by M.M1. Guyton and Desormes. By M.

DARRACO,

مد

DARRACQ.-M.M. Guyton and Desormes having published, in the 3d vol. of the Memoirs of the Institute of France *, an account of some experiments, from which they asserted that the composition and decomposition of the two fixed alkalis and of some of the primitive earths had been effected, M. DARRACE was induced to repeat these experiments; and, having described the niode which he adopted, together with the results, (which certainly appear to be decisive,) he thus concludes.

If the experiments which I have described in the course of this memoir be exact, and if I have properly observed the phænomena afforded by them, the result must be that the facts announced by M.M. Guyton and Desormes, although for the greater part correct, do not lead to the conclusions which they have inferred, on account of the nature of the substances employed by them ;-that, at least for the present, the alkalis and earths must remain in the class of simple or undecomposed bodies ;-that the experiments of these philosophers do not prove that pot-ash is formed of lime and hydrogen ;-that magnesia and azote produce lime ;--that alumine and azote consti. tute magnesia ; -and, in short, that magnesia and hydrogen form soda.- I do not, however, assert that these are simple substances, but only that the facts lately brought forwards are not competent to prove the contrary.

Observations on the Existence of Phosphorus in Sugar. By M. BOULLAY.—This chemist had occasion to prepare sulphureous acid, by distilling a mixture of sulphuric acid and sugar ; and he says that he obtained a considerable quantity of phosphorated hydrogen gas. He has not, however, been able to discover phosphorus, nor any of its combinations, in sugar.

Reply to the Remarks of M. Dartigues, &c. &c. concerning Barytes and Strontites. (See p.522,3.) By M.PAISSE.—This reply evinces that its author persists in his former opinion : but we do not deem it necessary to transcribe the particulars of the paper.

On the Electricity called Galvanism. By M. VOLTA. This excellent paper contains the author's system of the theory and doctrine of galvanie electricity: but we must refer our readers to the original, because an abridgement of it cannot be brought within the limits necessarily prescribed by the nature of our work.

Memoir on Medicinal Spirituous (alcoholiques ) Tinctures. By M. PARMENTIER.- Instead of the medicated wines which are sold by the druggists, and which often become spoiled, or which are of unequal qualities, M. PARMENTIER recommends tinctures to be made with diluted alcohol; so that, by the ad. dition of these tinctures to wine, any of the medicated wines * Sce p. 519. of this Appendix,

may

may be immediately prepared, and, by a due observance of the proportions of the tincture, their medicinal quality will always be uniform.

An Examination of different kinds of Pot-ash, with simple Methods of ascertaining the Proportion of Alkali and of other Salts which they may contain. By M. VAUQUELIN.-M. V. 25certains the quantity of alkali by the proportion of nitric acid required to effect saturation : but, previously, the density of the acid must be determined, as well as the degree of it which is necessary to sacurate any given quantity of pure potash.—The proportion of sulphuric acid in sulphate of pot ash is determined by nitrate of barytes, and that of the muriatic in the muriates which may be present, by nitrate of silver. The author then states the proportion of the various substances contained in six species of pot-ash, as follows:

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Names of the Pot-ashes.

Pot. of Treves.

1152

| 165 44 24 | 199=1152
Pot. of Dantzic.

1152 603 152 14 79 30451152
Pot. of Vosges.
| 1152 | 414 | 148 | 510 | 34 | 30431152

A Letter from M. Van MARUM to M. Volta, containing an Account of some Experiments made with the Electrical Pile. The facts detailed in this long letter are numerous, but not very striking. We shall the retore refer our readers to the original.

Report made to the National Institute on the Experiments of M. Volta. In this paper, the principles of M. Volta's theory of the Galvanic Electricity are stated.

Observations on the Combination of the Tartareous Acid with the Salifiable Bases, &c. &c. By M. THENARD.- We noticed a

report

report on this memoir in our last Appendix, p. 491. in an article on the Chemical Annals.

Memoir on a neru Combination discovered in Zaffre, which M. Brugnatelli has supposed to be Cobaltic Acid. By M. DARRACQ.M. Brugnatelli, in a memoir printed in vol. xxxiii, p. 113. of the Chemical Annals, gave an account of some experiments on the grey oxide of Cobalt, commonly called Zaffre ; from which he inferred that this substance contains a peculiar me. tallic acid, and which he therefore has denominated cobaltic acid. M. DARRACQ, however, on repeating these experiments, has discovered that the acid substance, which combines with ammonia and with water, is not (as M. B. supposed) cobalt converted by oxygenation into an acid, but an arseniate of cobalt rendered soluble by an excess of the arsenical acid. In order to prove this in the most evident manner by synthesis, M. DARRACO dissolved oxide of cobalt in arsenic acid, evaporated to dryness, and treated the residue with distilled water; after which, this solution was found to possess all the properties of the pretended cobaltic acid. 'Extract of a Letter from M. VAN MARUM to M. Berthollet. M. VAN MÁrum here relates that he has produced effects similar to those of the electrical pile of M. Volta, as far as the decomposition of water is concerned, by passing a current of electric cal fluid from a common machine through a tube containing water. He employed, for this purpose, very fine iron wire inserted in thermometer tubes, which were introduced and fixed at a proper distance in the opposite extremities of a larger tube containing the water.- This discovery of M. VAN MARUM, however, has been anticipated by the ingenious experia ments of Dr. Wollaston, published in the Phil. Trans. for 1801, p. 427, which we noticed in our late review of that volume* The only difference is, that the wire employed by Dr. Wollaston was of gold, while the experiments of M. VAN Marum were made with iron wire.

Description of a Stove on the Principle of the Swedish Fire-place, with Registers to admit warm Air. By M. GUYTON.--This paper cannot be understood without the plate.

Observations on the Proof of Pot-ash, by the Administrators General of Gun Powder and Salt Petre.— Nitrate of lime has been hitherto employed for this purpose, but nitrate of strontian is found to answer much better. For the particulars, the original memoir must be consulted.

Observations on Dying with Madder; and a simple and certain Mode of obtaining, with the greatest Beauty and Solidity, the Colour * See Rev. for March last, p. 300.

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