ACE

ACE

( <

form of vinegar. Radical vinegar is equallyunchanged by this procefs. p Thefe and otherexperiments feem to decide the quellion, thatthe difference between the two does not devpend on a different degree of oxygenation of thetrue acid bafe.

From the prefent ftate of our knowledge onthis fubjeCt, we may take the following opinionas the moil probable, namely, that acetous acid,though prepared from common vinegar by dif-tillation, retains a confiderable quantity of afoluble, mucilaginous, or extractive matter,which, without entering into the compofition ofthe acid, or actually adding to its bafe, (thougheompofed of the lame materials) remains dif-folved by the acid into a kind of faponaceouscompound: that it (fill adheres to the acid inits various alkaline, earthy, or metallic falts,and oppofes fome obftacle to their cryftalliza-tion, but that, when thefe falts are expofed tothe action of heat, or of the ftronger acids inclofe veffels, much of this extractive matter isfeparated from the vinegar either by formingcarbonic acid, or by remaining behind in acarbonaceous Hate, and the acetous acid bythis reparation only, and not by any hyperoxy-genation, becomes converted into the acetic, orradical vinegar. Hence it will follow, that inverdigris for example, the acid before diftilla-tion is ftili acetous, but during this procefs, theadhering carbonaceous extract turns to carbonicacid, by taking oxygen from the oxyd of copper*which laft therefore is left nearly in the metallicftate, whilft the acetous acid rifes, fimply freedfrom the extraCt which malked part of its acidproperties, and appears in its purer form ofradical vinegar.

Concentrated vinegar may be made to unitewith alcohol into a true ether, though withmore difficulty than the mineral acids.

Diftilied vinegar does not diffolve any of thetrue refins, but has fome action on the gum-refins.

It diffolves the acrid matter of plants, fuch asof the fquill, meadow-faffron, &c. which is thecompofition of fome medicinal vinegars. Thefolution is made by digefting the fubftance inten or twelve parts of vinegar for a few days.

It thickens fat oils, and diffolves the effentialin confiderable quantity when concentrated.Mr. Weftendorf diffolved eighty grains of oilof rofemary in four hundred and eighty grainsof his radical vinegar. Common diftilied vine-gar has little more action on thefe oils thanWater. When mixed with the brown empyreu-

» Darracq. A

)

matic oil of burnt vegetable matter, it forms *peculiar modification of this acid, long knownunder the name of pyromucous, pyrotartarcous, and.pyroligneous acids. (For this fee the next article*Acetous Acid. (Empyreumatic).

Common diftilied vinegar has little moreaCtion on camphor than water. The concen-trated acid however diffolves it pretty largely.The camphor is moftly feparable again by-water.

The ftrong acid fparingly diffolves vegetablegluten. On ftarch it has no operation. Gum-arabic and the other mucilages readily dif-folve in vinegar. A mucilage made with dif-tilled vinegar may be ufed as a cement, like thewatery mucilages, and with this advantage, thatit is very little fufceptible of mouldinefs.

Jelly is firft coagulated by the affufion ofvinegar, and afterwards diffolved.

It coagulates the albumen of milk, blood, andferum, but does not diffolve it.

It fhews a little a6iion on animal gluten.

The ufes to which the acetous acid in itspurified ftate is applied, are not very numerous.The moft important is in the manufacture offugar of lead and verdigris. It is ufed largely inmedicine. None of the acetites, befides thofe ofcopper and lead, are employed to any extent,except in pharmacy and in the laboratory.

The tefts to difcover the prefence of acetousacid in any mixture, are not very obvious ordireft. If the fubftance to be examined con-tains the acid in an uncombined ftate, it fhouldfirft be faturated with an alkali, and evaporatedvery gently to drynefs. Then the affufion of afew drops of fulpliuric acid on a fmall portionof the refidue, aflifted by a gentle heat, willdifplace the acetous, and give the agreeablepungent acid vapour by which this latter ischaracterized. Afterwards if the quantity ofmaterials be fufficient, the neutral fait may bediflolved out of the whole refidue, and cryftal-lized, and its nature thus detected by thofe whoare fkilled in the practical part of chemiftry.

The order of the affinities of this acid arebarytes, potafh, foda, ftrontian, lime, ammonia*magnefia, alumine, and the metallic oxyds, (fup-pofed to be in the fame order as with thefulphuric acid.)

ACETOUS ACID. Empyreumatic.

A great number of vegetable fubftances whenftrongly heated in clofe veffels, fo as to deftroytheir organization and texture, yield, amongother produCts, a coafiderable quantity of 4ftrongly empyreumatic, bitterifh, pungent, foufc1. Ch.T.41.