Chloro-cyanide of Potassium and Mercury, 343 



15 grs. of the salt yielded by the 1st experiment, 

 Mercury 8*6 grs. = 10*81 of bicyanide of mercury. 

 3* of chloride of potassium. 



13-81 

 2nd Experiment. 



Mercury 8*6 = 10*81 bicyanide of mercury. 

 3*40 chloride of potassium. 



14*21 

 By calculation, assuming the salt to be composed of an 

 atom of each of its constituents. 



1 1 *29 1 bicyanide of mercury. 

 3*708 chloride of potassium. 



14*999 



The numbers obtained by experiment approach sufficiently 

 near to those which result from calculation to warrant the 

 conclusion, that the double salt is composed of an atom of each 

 of its constituents, and may be thus represented : K CI 

 + Hg 2 Cy, or, 



Bicyanide of mercury 1 atom = 254 



Chloride of potassium 1 atom = 83*42 



337*42 atomic weight 



In 100 parts 75*277 of salt. 



24*723 



100*000. 



I may observe that in these experiments and calculations, 

 the atomic weight of chlorine has been taken as 35*42, that 

 being the number somewhat recently announced by Turner, 

 and agreeing nearly with that deduced from the experiments 

 of Berzelius. 



July 3, 1837. R. H. Brett. 



P.S. Since sending the preceding analyses for insertion in 

 the Philosophical Magazine, I have been informed by Mr. R. 

 Phillips, that the bromo-cyanide of potassium and mercury 

 has been described, and an analysis given by M. Caillot in 

 the Journal de Pharmacies tome xviii. p. 351. This salt is 

 called by Caillot the cyan o-hydrargy rate of the bromide of 

 potassium, believing as he does that the bicyanide of mercury 

 plays the part of the electro-negative or acid element, whilst 

 the bromide of potassium takes upon itself the electro-positive, 

 or base function : his mode of obtaining the salt is much the 

 same as that which I have described. M. Caillot considers 



