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Of these acetites the metallic bases of thefour first were left after the process in the re-guline state, the iron was the black oxyd, thezinc the white oxyd, and the manganese thebrown oxyd. The enormous difference instrength of acidity which these products shew,must immediately strike the reader. The authorinclines to the opinion that in proportion to thegreater difficulty of the reduction of the metal-lic base is the quantity of spirit yielded and ofacid destroyed. Thus the acetite of silver whichis reduced with the greatest ease, gives an acidcf much greater strength than the others, butno ascertainable quantity of spirit. On theother hand the acetite of lead, which is reducedwith more difficulty, and the acetite of zincwhich is not reduced at all, give a very weakacid but more spirit. It must be acknowledgedhowever that the production of spirit bears noproportion to the destruction of acid, so thatno argument can be hence derived of the con-version of the latter into the former.

When the acetites of potash and of soda are■distilled per sc, they yield a more spirituous andless acid product than any of the metallic ace-rites. The product from dry acetite of barytesTad the specific gravity of only .84-58, did notredden vegetable colours, but contained so con-centrated a spirit that it was necessary to addwater to enable carbonat of potash to produceany separation of spirit, and then the quantityof spirit separated was more in bulk than theentire original product of the distillation. Hencethe spirit was in a more condensed state before,than after the separation. Mr. Chenevix hasfound the acid product distilled from acetitedStiver to contain the purest and strongest aceticacid and the least mixed with spirit. Its specificgravity was 1.0656 when undiluted, and itssaturating power estimated at 107.309. Whengradually lowered by water, the specific gravityat first enrreased to 1.0733, but after this pointagain diminished by every subsequent dilution.This anomaly in the change of specific gravitycannot be accounted for here by the presenceof pyro-acetic spirit, since none was detected,and the author therefore ingeniously attributesit to the strong tendency of crystallization at amoderate temperature, which this very concen-trated acid possesses, and which probably actsas it does with water to produce an expansionof the liquid as it cools down to its point ofcongelation. The fact of the ready crystalli-

zation of the acid is undoubted, and this appearsnot to be owing to the presence of any spirit orextraneous matter, but rather to depend on thedegree of concentration of the acid itself.

It has been maintained by some chemiststhat prussic acid and ammonia are among theproducts of the distillation of the acetates. Thishowever is denied both by Mr. Chenevix and byTromsdorfF. The latter chemist d distilled ace-tite of soda, acetite of lead and acetite of pot-ash, separating the volatile portion from theresidue. The former was passed through anignited tube, and carbonic acid, carburetted hy-drogen and empyreumatic oil were produced,but no prussic acid nor ammonia appearedeither in this or in the fixed residue.

The latest analysis of acetic acid that we pos-rsess, is one of a very interesting series on variousanimal and vegetable substances, performed byMessrs. Gay-Lussac , and Thenard/ The modeof analyzing is original,being by combustion withoxymuriat of potash, as will be further describedunder the article Analysis. The acetic acidwas procured from acetite of potash by sulphuricacid, without any artificial heat, and the acidobtained was quite free from any admixture ofthe sulphuric. It was first boiled with carbonatof barytes, and the resulting acetite of baryte$dried in the heat of boiling water. Thirtygrammes of this salt were dissolved in waterand decomposed totally by sulphat of ammonia,and the sulphat of barytes, wlien ignited,weighed 25.445 grammes, of which the barytes,according to the received proportions, form*67 per cent, and hence the composition of theacetited barytes dried at a boiling water heat,is 43.17 per cent, of acetous acid, and 56.83barytes.

This acetite was then ignited with oxymuriatof potash, and the acetic acid when reduced toits ultimate elements, carbon, oxygen, and hy-drogen, gave the following proportions:

Carbon 50.224, oxygen 44.147, hydrogeij>5.629.

Or, supposing all the hydrogen to be unitedto its saturating proportion of oxygen to consti-tute water, the result will be,

Carbon 50.224, water 46.911, oxygen inexcess 2.865.

Four other vegetable acids were analyzed bythese chemists in the same manner, namely,the oxalic, the mucous, the tartaric, and theycitric, and the general results are as follow ;

i Recherches Physico-Cliimiques, See. tom. 2.

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* An. Chira. tom, 58.