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III. Account of a Series of Experiments, under tahen zu'ith the 

 Viciu of decompofmg the Muriatic Acid, By Mr. WIL- 

 LIAM Henry *. 



Mc 



-ODERN chemiftry/, notwithftanding its rapid advance- 

 ment during the few laft years, ftill prcfents to its cultivators 

 fcveral interefting objects, both of analytic and fynthetic in- 

 quiry. Among the former, the decompofition of the muri- 

 atic and of certain other acids holds a diftinguiflied place ; 

 for our cuviofity rcfpefting the nature of thefe bodies is 

 ftrongly excited by the influence which the difcovery would 

 have on the oeneral doctrines of chemical fcience, as well as 

 on the explanation of individual fafts. The theory of the 

 formation of acids, for example, one of the mod important 

 parts of the new fyfiem of chemiftry, muft be regarded as 

 incomplete, and liable to fubverfion, till the individual acids 

 now alluded to have been refolved into their conftituent 

 principles. To the bed of my knowledge, however, we are 

 not in poflcffion of a fingle fait that gives the fmalleft infight 

 into the conftitution of the muriatic acid ; and the attempts 

 to eflecl its analyfis can only therefore be direfted by the 

 analogy of the decompofition of other bodies, which, from 

 fimilarity of character, are arranged in the fame clafs. 



One of the firft objefts in the analyfis of a compound body 

 fiiould be, its complete feparation from all other fubfl:ances, 

 which, by their prefence, may tend to introduce uncertainty, 

 into the refults of the proceires that are emplojed. But it 

 is feldom that a fimplicilv fo defirable can be obtained in 

 the obje6ls of chemical refearch; for, agreeably to a known 

 law of affinity, the laft portions of any fubftance are fepa- 

 rated with peculiar difficvdly ; the force of attra6lion appear- 

 ing to increafe as we recede from the point of faturalion. In 

 a liquid ftate, the muriatic acid is a totally unfit fubjeft for 

 analytic experiment ; for, in the ftrongefl; form under which 

 it can be procured, it ftill contains a large proportion of 

 water. This watery portion, befides the complexity which 



* From T'ranfailions of ibf Royal Society of London for iSoo. 



E e ? it 



