Mr Johnston on a solid form of Cyanogen. 79 



Carbonic acid, 2.2 inches = 1.025 grs. 



Azote - 1.1 = .3261 



Oxygen 1.4 = .4748 



Weight of gas given off, — 1.826 



Loss of weight in the experiment = 2.6 



Deficiency, .774 grs. 



Now the carbon in 2.2 inches carbonic acid = .2794 grs. 

 and 1.1 azote = .3261 



.6055 



Weight of substance analyzed, z=z .7 



Deficiency, = .0944 grs. 



But .0944 X 9 = .8496 gr. not greatly exceeding the first 

 deficiency, which was therefore due to the formation of water, 

 a very small quantity of which had most probably remained 

 in the tube. 



We have consequently the weight of hydrogen in the sub- 

 stance = .0944 grs. 



Atom of Cyanogen, 

 and .605 : .0944 : : 3.25 : .505 

 But .505 is almost exactly 4 atoms hydrogen. 

 Therefore, in this state and dried at 212°, the substance, as 

 deposited from the alcoholic solution, consisted of 



Cyanogen or its elements, 1 atom 



Hydrogen, - - . 4 atoms 



By farther heat the hydrogen is driven off in combination 

 probably, and there remain simply the elements of cyanogen. 



Instead of filtering the alcoholic solution, the sediment may 

 be obtained by distilling it in a retort. In this case also the 

 colourless spirit which comes over being set aside, again be- 

 comes yellow, then dark red, and deposits a further sediment, 

 provided it have not already stood so long as to give time for 

 a deposition in the solid state of all the cyanogen it contains. 



The solid matter remaining in the retort being taken out. 



