1835.] Improvements in Science. 191 



of cyanogen thus obtained consists of brilliant needles, 

 possessing a strong disagreeable odour. To determine the 

 quantity of chlorine, the salt was dissolved in alcohol, 

 ammonia was added, and the liquid boiled with a great 

 quantity of water until all the spirit was volatilized. 



Nitric acid was then added, in excess, and precipitation 

 produced by nitrate of silver. The composition of the 

 chloride of cyanogen was in this manner determined to be 



Chlorine . . . 57*03 

 Cyanogen . . . 42-97 



100-00 

 or equal atoms of chlorine and cyanogen. Chloride of 

 cyanogen dissolves in absolute alcohol without alteration. 



8. Cyanamide. — If chloride of cyanogen is moistened with 

 ammonia, and gently heated, it loses its crystalline form, 

 and is reduced to a white powder, which is slightly soluble 

 in boiling water, and is precipitated on cooling in flocks. 

 The same substance is obtained by passing ammoniacal gas 

 over chloride of cyanogen in powder. A white powder is 

 the result, which maybe purified by washing. The chlorine 

 which it contains is not removed by ammonia. Potash 

 disengages ammonia from cyanamide. Liebig considers it 

 analogous in its composition to oxamide, and to a chloride 

 of cyanogen. 



Uric Acid. — Liebig states that he was encouraged to make 

 the preceding researches in the hope of finding a new com- 

 bination which would throw some light upon the composi- 

 tion of uric acid. Liebig considers the determination of 

 Dr. Kodweiss, with respect to the proportion of azote, to 

 be nearer the truth than any other. He himself makes the 

 composition of uric acid : 



Calculated. Experiment. 



Carbon ... 36-11 - 36-073 



Azote .... 33-36 - 33-361 



Oxygen ... 27-19 - 28*126 



Hydrogen. . 2-34 - 2.441 



Method of procuring Oxide of Chromium in Crystals. — 

 Wohler has found that the green oxide of chromium, which 

 is well known as a green powder, may be obtained in the 



