[ 365 ] 



LXVIII. Further analytical Experiments relative to the Cov- 

 stiluiion of the pn/ssic, of the fern/retted chyazic, and of 

 the sulphuretted chijazic ykids ; and to that of their Salts-, 

 together -with the yjpplicafion cf the Jto?uic Theory to the 

 Analyses of those Bodies. By Robert Porrett, jun. Esq. 

 Communicated hy W. H, Wollaston, M.D. Sec. U.S.* 



± HE Royal Society did me the honour of printing in the volume 

 of their Transactions for last year, a ])aper of mine on the na- 

 ture of the salts termed triple prussiates, and on acids formed 

 by the union of certain bodies with the elements of the prussic 

 acid. 



In that paper I endeavoured to prove that the elements of 

 the prussic acid would combine with a certain proportion of 

 black oxide of iron, and form a peculiar and hitherto unknown 

 acid, for which I proposed the name of the ferruretted chyazic 

 acid. I showed that this was the real acid portion of the salts which 

 had received the erroneous appellation of triple prussiates, and 

 that the property of combining witli the prussic acid, so as to 

 change its nature, and increase its acid properties, was not con- 

 fined to the black oxide of iron, but was possessed probably by 

 many other bodies, but certainly by sulphur, which formed with 

 It another acid, for which 1 proposed the name of the sulphu- 

 retted chyazic acid. The paper also contained some anahtical 

 researches into the proportions in which the elements of these 

 new acids are combined in them, and also into the proportions 

 in winch they unite with different saline bases. 

 ^ My object in tliis paper is to add to the analyses contained in 

 tne lormer, two analyses which I have since made; and then to 

 apply to the whole the admirable theory of Dalton, by which the 

 proj)ortions in which bodies can combine are conceived to be 

 governed by the relative weights of their chemical atoms, and 

 also Berzehus's addition to this theorv, by which the combina- 

 tions of oxides with one another are conceived to take place 

 in such a manner, that the oxygen contained in one of these 

 bodies IS either eciual to or is a multiple bv a whole number of 

 the oxygen contained in the others. 



I begin with describing the two analyses to which I have just 

 alluded. '' 



Analysis of Prussiate of Mercury. 

 A. Fifty grains of this salt finely pulverized were kept: at tlie 

 temperature of 212° for six hours, at the end of which time 

 they weighed exactly the same as before. 



* from tlie I'liilosopliical Transactions for 1815, part ii. 



B. Fortv 



