1818.] Triple Prussiate of Potash. 215 



being 16-59 water, 34-31 acid, and 49-10 barytes, I now find 

 to be, 



Water 11-0 



Acid 41-5 



Barytes 47-5 



100-0 



If we reckon the weight of an atom of the acid from this 

 analysis, we shall find it 84-7, approaching very nearly to the 

 weight deduced from my analysis of the ferruretted chyazate of 

 potash by tartaric acid. 



So far then there is nothing in the nature of these salts irre- 

 concileable with the atomic theory ; but the principal difficulty 

 yet remains, and is contained in the following question : 



How is the chemical constitution of this acid to be reconciled 

 with the weight for it, deduced from the analysis of the ferruret- 

 ted chyazates ? 



In answer to which, I beg to propose the following explana- 

 tion, which, although not yet fully confirmed by experiment, I 

 have every reason to believe is the true one. 



Ferruretted chyazic acid is not/ in my opinion, a compound 

 of prussic acid and iron, as Dr. Thomson imagines, but a com- 

 pound of the elements of two atoms of prussic acid — an atom 

 of azote, + an atom of iron, or in other words, it is composed of 



4 atoms carbon = 30-16 



1 atom azote = 17-54 



1 atom iron = 34*50 



2 atoms hydrogen — 2*64 



84-84 



Its weight will, therefore, be 84-84. Ferruretted chyazate of 

 potash and ferruretted chyazate of barytes will each consist of 

 an atom of acid, an atom of base, and two atoms of water ; 

 hence their true composition will be as follows : 



Ferruretted chyazate of Potash. 



Ferruretted chyazic acid . . 50-93 84-84 1 atom 



Potash 35-48 59-10 1 atom 



Water 13-59 22-64 2 atoms 



100-00 166-58 



Ferruretted chyazate of Barytes. 



Ferruretted chyazic acid . . 41-49 84-84. 1 atom 



Barytes 47-44 97-00 1 atom 



Water 11-07 22-64 2 atoms 



100-00 204-48 



On calculating from these data what should be the gaseous 



