■■ 



on some Hydrargyro-Cyanurets. 357 



supported on a piece of platinum foil at the mouth of the 

 crucible, so as to prevent the possibility of any potassa 

 existing in the state of bi-sulphate ; the crucible, after the 

 ignition, was again weighed, when, on subtracting its 

 former weight from the latter, it was found that the 

 weight of the sulphate of potassa was 1'23 grs. = 0'93 grs. 

 of cyanuret of potassium = 1 equivalent. 



In order to estimate the quantities of mercury and cya- 

 nogen, the following process was adopted : — ■ 



10 grs. of the salts in crystals were dissolved in water, to 

 which a solution of sidphuret of potassium was added very 

 slowly, until no further precipitate took place ; by this 

 means the whole of the mercury was precipitated as bi-sul- 

 phurets, which was placed on a weighed filter, and well 

 washed with distilled water ; after thoroughly drying the 

 filter it was weighed, when, on deducting its former weight 

 from the latter, the difference was 8*0 grs. : Bi-sulphuret of 

 mercury = 9* 10 grs. bi-cyanuret of mercury = 2 equivalents. 

 The solution filtered from the bi-sulphuret of mercury con- 

 tained the whole of the cyanogen present in the salt, now in the 

 state of cyanuret of potassium ; to this solution nitrate of silver 

 was added until the whole of the cyanogen was precipitated 

 as cyanuret of silver, which was placed on a weighed filter, 

 and well washed with distilled water; it was then transferred 

 to a weighed platinum capsule, and converted into chloride 

 of silver, by acting on it with muriatic acid; after driving 

 off the excess of muriatic acid by heat, the filter was burnt 

 in the capsule, and the whole heated to a temperature 

 short of fusion ; on deducting the weight of the capsule, 

 and the ashes of the filter, from the weight of the whole, 

 the weight of the chloride of silver was 10'27 grs. = T89 

 grs. of cyanogen, = 5 equivalents, exactly corresponding 

 to the calculated quantity in the former analysis. 



Thus, then, 10 grs. of this salt contain, 



Of Cyanuret of potassium, 0"93 = I equivalent. 

 ,, Hi-cyanuret of mercury, 9*10 = '1 equivalents. 

 Water, 0-02 



10-05 

 The equivalent of this salt is 575 - 50 ; its composition may 

 be expressed in symbols, 2 (Hg + Cy s ) + (K + Cy). 



