1813.] Chlorine^ and its Compoimcts. 131 



unite with more than '677 of a g ra ' n to f° rm muriatic acid • so 

 that an evolution of hydrogen must take place to the extent of 

 •393 of a gr. or 15*04 cubic inches. Should it be preferred to 

 suppose horn silver composed solely of chlorine and silver, it 

 must yield, on analysis, 20-02 of muriatic acid, and 86*648 of 

 oxide of silver. 



Mr. J. Davy has, in his paper on the combinations of chlorine, 

 stated another analysis of horn silver, which, he observes, agrees 

 very nearly with that given by Klaproth, viz. 24-5 of chlorine 

 and 75-5 of silver. On this basis, the result of the analysis 

 should be 25-4224 of muriatic acid, and 82*4 of oxide of silver. 

 It must, however, be allowed, that if this difficulty, and some 

 others that will be stated immediately as attaching to Mr. J. 

 Davy's analysis, can be got over, it will answer very nearly to 

 the result of the above detailed experiment ; for 5*4375 grs. of 

 chlorine ought, on this estimate, to form 22*194 grs. of horn 

 silver. 



If oxide of silver, at the precise degree of oxidation in which 

 it has been stated to be found in muriate of silver (viz. containing 

 about 7*8049 per cent, of oxygen) be added to common muriatic 

 acid, there ought to ensue, on Sir H. Davy's theory (if Proust's 

 analysis be correct), an evolution of oxygen to the amount of 

 7*1 88 cubic inches for each 100 grs. of the salt formed, because 

 the hydrogen previously united to the chlorine, with which 75*6 

 grs. of silver can combine, is incapable of entering into combi- 

 nation with more than 3*95598 grs. of the 6*4 grs. of oxygen 

 which that quantity of silver holds in union with it. Or, adopt- 

 ing Mr. J. Davy's analysis of horn silver, the evolution of 

 oxygen should amount to 2 97 cubic inches; because jb'b grs. 

 of silver hold in combination 6*5 grs. of oxygen, of which only 

 5*51 grs. can enter into union with the hydrogen (*9224 of agr.) 

 set free from its combination with the chlorine. 



Again, in the process of separating chlorine from silver, there 

 ought to be an evolution of a little more than 15 cubic inches of 

 hydrogen for every 100 grs. because the silver requires 1*44402 

 gr. of oxygen more than can be furnished by the water sufficient 

 to afford *677 of a gr. of hydrogen to the chlorine. But, by Mr. 

 J. Davy's analysis, this evolution of hydrogen ought not to 

 exceed G*99 cubic inches, for 24*5 grs. of chlorine take '9224 

 of a gr. of hydrogen, and this quantity is capable of combining 

 with 5*51 grs! of the 6*5 grs. of oxygen required by the silver. 



The former part of the reasoning employed to obviate the 

 probable objection against the experiment which 1 have detailed, 

 would be in some measure incomplete, were I to overlook Sir H. 

 Davy's theory of the nature of the muriates. This I shall notice 

 as briefly W possible. 



Taking, then, the instance of muriate of potash, it appears 



I 2 



