MM. Pelouze aiid Richardson on Cyanogen. ?^39 



mixed with the particles of charcoal by wMch its surface had 

 been blackened. 



Concentrated and boiling sulphuric acid chars and decom- 

 poses it. In boiling nitric acid it undergoes no apparent 

 change. 



According to Sir David Brewster it polarizes light in 

 patches. 



Of an uncoloured portion selected for analysis from the centre 

 of the mass, 5* 14- grs. gave 15*97 of carbonic acid, and 

 6*765 of water. These quantities are equal to 



Experiment. Theory. 



1 atom of carbon = 76*437 = 85*910 85*965 



1 atom of hydrogen =12*479 = 14*624 14*035 



88*916 100*534 100* 



The excess of hydrogen is to be attributed to the unusual 

 quantity of moisture left in the oxide of copper, which the vo- 

 latility of the substance prevented me from heating sufficiently 

 high to permit the water to be wholly driven out. 



This substance therefore belongs to the group of which 

 olefiant gas is the best known type, and it differs from pa- 

 raffine chiefly in its tendency to crystallize, and to decompose 

 and blacken by long exposure to the air, or by the action of 

 concentrated sulphuric acid. In the last two properties it 

 agrees with theMiddletonite described in the preceding Num- 

 ber of this Journal, p. 261. 



Durham, March 1838. 



LVI. Researches upon the Products of the Decomposition of 

 Cyanogen in Water*, By MM. Pelouze and RicHARDSON.f 



/CHEMISTS have possessed up to the present time but 

 ^^ very incomplete notions respecting the alteration which 

 an aqueous solution of cyanogen undergoes when exposed 

 simply to the action of light. 



M. Vauquelin, who was occupied with this subject in 1818, 

 found that besides ammonia, and a peculiar black matter, 

 there was formed, by the action of cyanogen upon the ele- 

 ments of the water, three distinct acids, viz. carbonic acid, 



* This note is the first part of an examination which we have under- 

 taken upon the alteration which several azotized bodies undergo by the 

 action of water, heat, «&c., and upon the state of the azote in charcoals of 

 animal origin. 



t Communicated by Mr. Richardson. 



2 I2 



