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Cum Arabic , Starch, Sugar of Mill', Oakand Beech Wood, all agree with sugar in beingcomposed merely of carbon, and of oxygen andhydrogen in the proportions required, to formwater.
Mucous Acid. This acid was prepared byheating sugar of milk with nitric acid. Thesolution soon became turbid, and much mucousacid was deposited, which was well washed anddried in a boiling-water heat. This acid left noresidue whatever after calcination. On defla-grating a given portion of it with four times itsweight of oxygen in the above-mentioned appa-ratus, and estimating the oxygen and carbonicacid of the product, a considerable excess ofoxygen above the quantity required to formwater with the hydrogen of the mucous acidwas found, and hence the acid is considered ascomposed of carbon, water, and oxygen inexcess.
Oxalic Acid . This acid was not mixed im-mediately with the oxymuriat of potash, but wasfirst combined with lime (by being saturatedwith ammonia and precipitated by muriat oflime) and the dried oxalat of lime was calcinedby itself in a platina crucible, and thus found toconsist of 61.345 of acid and 3S.655 of lime.
A given portion of the oxalat of lime was thendeflagrated in the usual way with I f its weightof the oxymuriat, and the results analyzed as be-fore, but as a portion of the carbonic acid wasretained in the deflagrating tube united with thelime and muriat of potash, this was separatelyanalyzed by muriatic acid and the carbonic acidexpelled.
Tartareous Acid. This acid was extractedin the usual way from tartrite of lime by sul-phuric acid, but as it still retained a little of thislatter acid even after repeated crystallization, itwas dissolved in water and boiled with powderedlitharge added gradually till the liquor no longerprecipitated nitrat of barytes, by which meansall the sulphuric acid was got rid of. The leadin solution was then separated by a current ofsulphuretted hydrogen gas, and the clear liquidwhen evaporated gave pure tartareous acid. Itwas found impracticable however to make it intoballs with oxymuriat of potash and water, as itdeliquesced instantly on exposure to air.
The acid was therefore combined with lime,the tartrite of lime, dried at 212°, was found bycalcination to consist of 77.577 of acid and22.423 of lime, and this was further analyzedin the same manner as the oxalic acid.
the preceding acid. The citrat of lime consistedof 68.83 of acid and 31.17 of lime.
Acetic Acid . The acid here employed wasfirst expelled from acetite of potash by sulphuricacid, and then heated with an excess of carbonaiof barytes and the acetite of barytes evaporatedand dried. But as this acetite could not be ana-lyzed by simple calcination, (no continuance ofheat being able to expell from the barytes all thecarbonic acid formed by the combustion of theacetous) 30 grammes of the acetite were de-composed by sulphat of ammonia, and the sul-phat of barytes was transferred, while still wet,to a platina crucible, and gradually ignited, tillall the sulphat and acetite of ammonia adheringto it were expelled, and the sulphat of barytes re-mained pure. It weighed 25.443 grammes andcontained 67 per cent, of barytes; and fromthese data acetite of barytes dried at 2.12°. con-sists of 43.17 acid and 56.83 barytes. Thisaceiite was then deflagrated as the last, and theresults examined.
All the acids here examined contained anotable excess of oxygen, as will be seen in thetabular statement at the end of this article.
Resin of Turpentine, or Common Rosin..This was simply mixed with 12 times its weightof the oxymuriat and deflagrated in the appa-ratus. Scarcely any carburetted hydrogen wasproduced by the combustion, but carbonic acid,and much water, which last when collected andexamined was neither acid nor alkaline, and theresidue in the tube was pure muriat of potash.The large quantity of water produced indicateda proportional excess of hydrogen in the resin,so that by the usual mode of estimation thisresin contained carbon, oxygen and hydrogen inthe proportions for constituting water, and anexcess of hydrogen.
Copal, Wax, and Olive Oil , were analyzedin the same manner, some little difference beingobserved in the manipulation of mixing themwith the oxymuriat.
From the analysis of the above fifteen vege-table substances the authors consider that the fol-lowing importa..t inferences may be deduced,namely:
That a vegetable substance is acid wheneverthe oxygen which it contains exists in a largerproportion than will constitute water with thehydrogen present.
That a vegetable substance is resinous, oroily, or alcoholic, &c. when the oxygen is inless proportion than is required to form waterwith the hydrogen,.