ACE

ACE

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coppery fmell. This is the true radical vinegar,■which fhould be kept apart from the formerproduifl; in a well clofed bottle. The refidue isa red-brown oxyd of copper mixed with char-coal, which when the retort has been made redhot, to drive out the laft portions of acid,often lines the inlide with a cupreous metallic-looking pellicle. This oxyd is fometimes pyro-phoric.

Another and more economical procefs is thefollowing, given by M. Badolier: k mix equalparts of fulphat of copper and acetited lead,diftill as the laft, but with a more gentle fire.A very pleafant and extremely pungent radicalvinegar comes over, about a third of the weightof the ingredients ufed. 1 No gas, except theatmofpherical air of the veffel, is given out inthis procefs, which is effentially the fame asthe former, fince the perfect acetite of copperis firlt produced by the mixture of the two me-tallic falts, which mutually decompofe eachother, as foon as their affinities can begin tooperate. The acetic acid procured from thefalts of copper, is diftinguifhed by a lightgreenifh colour and a coppery fmell, whichmakes an unpleafant addition to the agreeablepungency of the acid. It is not neceffary tocryftallize the verdigris in the firft procefs, afolution of oxyd of copper in vinegar evapo-rated to drynefs, will anfwer the fame purpofe.An acid fimilar at leaft in moft fenfible proper-ties, may be obtained from the acetite of lead,not indeed by diftillation per fe, but by theaddition of fulphuric acid, for none of the me-tallic, or alkaline, or earthy acetites, that havebeen fubjeCted to experiment, will yield theiracid, undecompofed by fimple diftillation, ex-cept the acetite of copper. Six ounces of fulphuricacid, added to twelve ounces of fugar of lead,and diftilled with a gentle heat, will give fevenounces of a very concentrated cauftic vine-gar.™ In this however, as in moft of thofeproceffes where the naked fulphuric acid isadded, the product is contaminated towards theend of the diftillation, by fulphureous gasarifing from the partial decompofition of theacid by part of the carbonaceous balls of thevinegar.

Many experiments have been made, and ar-guments, adduced, on the queftion of the diffe-rence of the acetic and acetous acids, but furtherfadts are ftill wanting to enable us to decidewith certainty. It appears reafonable that inmaking the ccmparifon, we fhould only con-hder as proper acetous acid, fimple diftilled4 An. Ch. Tom. 37< 1 An , ch.Tom. 41. p *73.

vinegar, either in its common or watery ftate,or at moft concentrated by froft, which to all ap-pearance makes no other change than that ofdepriving it of a portion of its water. Theacid, concentrated by diftillation in any formwhatever, either from the alkaline or metallicacetites, or by charcoal, or by the affiltance offulphuric acid, may probably be confiderea asthe acetic, or radical vinegar, in one variety orother.

Diftilled vinegar, ftrengthened fimply by thefreezing of its watery part, differs from theacetic acid of verdigris in the following fenfibleproperties : its fmell, though powerful, is muchlefs pungent and ftimulating, the vapours ofthe latter being fo potent as almoft to fuffocateif ltrongly fnuffed up, and to excoriate thenoftrils and month : its tafte {hews the famedifference of intenfity: its fpecific gravity isnot eafily raifed higher than about 1.029,whereas that of the radical vinegar is about1.0404. When both acids are reduced to thefame fpecific gravity by diluting the radicalvinegar, the above difference in fenfible pro-perties is not very perceptible (the adventitiousodour of copper in the radical vinegar preparedfrom verdigris, always being put out of thequeftion) though fome chemifts affert that it isftill to be remarked.

When faturated with either of the fixedalkalies, and brought to cryftallize, the appear-ance of each fait is precifely the fame. If anequal quantity of each be fubmitted to deftruc-tive diftillation, the volatile products are fonearly the fame as to allow of no affignabledifference. However, the quantity of carbona-ceous refidue, according to Chaptal, n is lefs inthe fait with acetic acid (or what, to avoidconfufion, we fhall for the prefcnt call the radi-cal fait), than in the acetous; being only T ‘ rof the original weight in the former, and inthe latter. But the experiments of Darracq,conducted in the fame manner, are not fo con-clufive. Neither of thefe acids have any actionon metallic copper immerfed in them; theoxyd of this metal is diffolved by both, andfurnifhes a fimilarly cryftallized metallic fait jwith this notable difference however, that theradical acid diflolves the oxyd with much morefacility, and the folution cryftallizes muchfooner and eafier.

The acetous acid is in no degree changed bydiftillation with nitrous or oxymuriatic acid,fo that it does not appear to be fufceptible of ahigher degree of oxygenation whilft in the

Dolfus. Fharm, Ch. E r f*hr»ngen. "An.Ch Tom, *8. “Ail. Ch. T.41,