DECEMBER, 1809.

Engravings of the following Subjects, (In Two Quarto Plates :) 1. Figures lustrating the Crystallization of Endellion, by the Count de Bournon. 2. Diagrams for a Demonstration of the Cotesian Theorem; by Mr. P. Barlow.

I. On Vegetable Astringents. By John Bostock, M.D. Communicated by the Author

·

241

II. Memoir on the triple Sulphuret of Lead, Copper, and Antimony, or Endellion. By M. le Comte de Bournon, F. R. & L. S.

-

251

III. Of the Irritability of Vegetables. By Mr. Robert Lyall, Surgeon. Read at the Literary and Philosophical Society at Manchester, Oct. the oth, 1809. Communicated by the Author.

IV. Demonstration of the Cotesian Theorem, by Mr. P. Barlow

261

278

V. On the Influence of Electricity on Flame: by Mr. Leopold Vacca, Colonel of the 23d Regiment of Light Infantry.

283

VI. Of the Action of Phosphorus and oxigenized muriatic acid Gas on Alkalis: by Messrs. Bouillon-Lagrange and Vogel.

285

VII. On the Chemical Analysis of the Onion. By Messrs Fourcroy and Vauquelin.

290

VIII. Abridgment of a Paper on the Species of Carnivorous Animals, the Bones of which are found mixed with those of Bears in Caverns in Germany and Hungary. By Mr. Cuvier.

295

IX. Account of some Colours for Painting, found at Pompeii; by Mr. Chaptal. Communicated to the First Class of the Institute, March the 6th, 1809.

302

X. Remarks on the Introduction of Air into the Blood through the Lungs, in Answer to Mr. Acton. In a Letter from a Correspondent. 307

XI. Letter from Mr. Robert Bancks concerning the Meteorological Journal,

SUPPLEMENT TO VOL. XXIV.

Engravings of the following Objects: 1. Various Delineations and Sections of Grafts and Buds, from original Drawings after Nature, by Mrs. Agnes Ibbetson 2. Branch of a Portugal Laurel, from which the Bark had been accidentally separated. 3. Different Structures of several Kinds of Wood.

I. Memoir on the Triple Sulphuret of Lead, Copper, and Antimony, or En dellion. By M. le Comte de Bournon, F. R. and L. S.

321

II. On the Effects produced by the grafting and budding of Trees. In a Letter from Mrs. Agnes Ibbetson,

III. On the Defects of grafting and budding. By Mrs. Agnes Ibbetson.

337

346

IV. Experiments on Ammonia, and an Account of a new Method of analyzing it, by Combustion with Oxigen, and other Gasses; in a Letter to Humphry Davy, Esq. Sec. R. S., &c., from William Henry, M. D. F. R. S., V. P. of the Lit. and Phil. Society, and Physician to the Infirmary at Manchester.

358

V. Observations on the Composition of Ammonia. By Mr. Berthollet, jun.

374

VI. Analysis of the Chinese Rice-Stone, with some Observations on the Yu. By Mr. Klaproth.

375

VII. On the Effect of westerly Winds in raising the Level of the British Channel. In a Letter to the Right Hon. Sir Joseph Banks, Bart. K. B. P. R. S. By James Rennel, Esq. F. R. S.

VIII. On Dead Lime. By Mr. Bucholz.

379

381

IX. On the Muriates of Barytes and of Silver. By Berthier, Mine Engineer.

A

JOURNAL

OF

NATURAL PHILOSOPHY, CHEMISTRY,

AND

THE ARTS.

SEPTEMBER, 1809.

ARTICLE I.

On the Union of Tan and Jelly: by JOHN BOSTOCK, M.D.

SIR,

To Mr. NICHOLSON.

DURING the course of the last spring I was engaged in Purpose of the

quiry.

a set of experiments, which may be considered as a conti- author's innuation of those formerly made on the analysis of animal fluids. My object was to enable the operator to apply the tests, which indicate the existence of the principal constituents of these fluids, albumen, jelly, and mucus, so as not only to discover the qualities of the compound, but the quantities of its ingredients. The results of my experiments have been, upon the whole, unsuccessful; and I have at present chiefly to announce the failure of the different expedients, which I employed to attain my object. It may not, however, be altogether useless, to lay my experience

* See Journal, vol. IX, p. 244.

VOL. XXIV. No. 106 SEPT. 1809.

B before

Jelly.

ate to the

quantity present.

before your readers; not merely because I have it in my power to state some few facts, that may be considered as an addition to our stock of knowledge, but still more, because I may induce some one more skilful than myself, to point out a method of accomplishing what I have hitherto attempted without success.

The substance upon which I first operated, and to which I shall principally confine my attention in the present paIts characters. per, is jelly; the characteristics of which are its solubility in water, its forming an insoluble compound with tan, and the property which its aqueous solution possesses of concreting by cold, and being redissolved by the application Inquiry whe- of heat. The problem which I was anxious to solve was, ther the preci- whether the compound of tan and jelly be uniform, so that pitate by tan be proportion- by saturating the gelatinous part of a solution with tan, and collecting the precipitate, we may, from its weight, (the quantity of tan employed being known) ascertain the amount of the jelly previously contained in the fluid. From the experiments that had been performed on the subject, Mr. Biggin's particularly those of Mr. Biggin and Mr. Davy, I conceived, attempt to ascertain the prothat this would be found to be the case. The object of Mr. portion of lan. Biggin's experiments was to ascertain the proportion of tan in different barks, for which purpose he formed similar infusions of them, and precipitated the tan from each by a solution of glue. He employed the solution of glue always of the same strength, and by collecting the precipitates, he judged of the quantity of tan that had united itself to the glue, and thus of the proportion of it in the bark. The experiments are important, as comparing the different barks with each other, and thus ascertaining their respective value as substances to be employed in the manufacture of leather; but it is obvious, that, unless the compound of tan and glue be uniform, they do not show the absolute quantity of tan in any given weight of bark. Mr. Davy, in his shows the pre-experiments on astringent substances, has pointed out, with portionate to his accustomed sagacity, the different effects that are prothe strength of duced in the union of solutions of tan and jelly, according to their degree of concentration; and has proved, that in

Mr. Davy

the solution.

Phil. Trans. 1799, p. 260.

proportion

proportion to the strength of the solution, either of jelly or of tan, will be the weight of the precipitate obtained. It would appear, that, when the solutions are much diluted, the attraction of both the jelly and the tan for the water, to a certain extent, counteracts their attraction to each other, and thus prevents a portion of them from being removed from the fluid. Mr. Davy, however, as well as Mr. Both suppose Biggin, evidently seems to have conceived, that the sub- the precipitate stance which was precipitated in all instances possessed the compound. same properties, and consisted of a uniform compound of the two ingredients. This opinion is the very foundation of the method which he employed in his analyses, and is directly asserted in different parts of his papers t.

to be a uniform

With this impression it was, that I entered upon a set of The author's proceeding the experiments, which may be considered as the converse of converse of those of Mr. Biggin and Mr. Davy. The object of these theirs. chemists was, by the agency of jelly, to remove all the tan from a vegetable infusion, and to estimate its quantity from the weight of the precipitate; while mine was, by means of tan, to ascertain the quantity of jelly that was contained in

any animal fluid. In pursuing this investigation, the first A uniform re: point was to determine upon the most proper substance to agent requisite. employ as the reagent; for as it is difficult, if not absolutely impossible, to procure tan in a state of perfect purity, it became necessary to discover some vegetable infusion, which should always possess similar properties, and in which the quantity of tan should be known, without having recourse to any long calculation. My attention was naturally, in the first instance, directed to galls; and I expected, that Galls. by employing equal weights, infusing them in equal quan tities of water, and for an equal length of time, fluids would have been formed always containing equal quantities of tan. But upon making repeated trials, I find that this

is not the case; and it would appear from all the experience Not uniform in their nature, I have had upon the subject, that two parcels of galls will scarcely ever be procured, which will precisely agree in their

Phil. Trans. 1803.

+ Phil. Trans. 1803. Nicholson's Journal, vol. V, p. 259, 269, &

alibi.

B 2

nature.