1835.] Improvements in Science. 185 



of bodies differing very materially in their nature from the 

 substance in which they were previously combined . To ascer- 

 tain if this fact held good in reference to inorganic substances, 

 Liebig submitted to examination a ternary compound, which 

 he formed in the following manner : (Ann. de Chim. lvi.) He 

 passed through a solution of sulpho-cyanodide of potassium a 

 current of chlorine gas . When boiled with dilute nitric acid 

 an orange-yellow body precipitated, which, in its composi- 

 tion, was identical with the radicle of hydrosulphocyanic acid. 

 Hence, he considered it as sulpho-cyanogen. This substance, 

 when heated, is decomposed, and a quantity of sulphur and 

 sulphuret of carbon comes off, while a yellow powder remains, 

 which was employed by Liebig in his subsequent researches, 

 Liebig terms this citron-coloured powder mellon. When 

 exposed to a temperature at which glass melts, it is decom- 

 posed into pure cyanogen and azote. Analyzed with oxide 

 of copper, carbonic acid and azote are procured in the pro- 

 portion of 3 to 2. He considers it composed of 



Carbon . . 458-622 

 Azote . . . 708-144 



1166-766 

 and explains its formation by conceiving 2 atoms of sulphuret 

 of carbon = 2 C -j- 4 S and 4 atoms of sulphur to be 

 subtracted by the heat from 4 atoms of sulpho-cyanogen, 

 whose composition he states = 8C + 8A-f8S. There 

 remains therefore 6 C 4- 8 A. 



Mellon, when heated in dry chlorine gas, combines with 

 it and forms a white body, possessing a strong smell, and 

 acting upon the eyes. The same substance may also be 

 procured by heating together two parts chloride of mercury 

 and one sulpho-cyanodide of potassium. Mellon may be 

 produced by heating sulpho-cyanodide of potassium in a 

 current of dry chlorine gas. With potassium mellon com- 

 bines and forms a transparent easily fusible mass, which 

 dissolves in water, imparting to it a taste of bitter almonds, 

 precipitating the metals not as cyanodides, and is decom- 

 posed by the agency of acids. 



2. Melam.— This substance is procured from hydro-sulpho- 

 cyanate of ammonia, a salt which is formed by distilling 

 together two parts of muriate of ammonia, and one part 



