132 



Dr. M. W. Travers. The Origin of the Gases 



If this is the case, the mineral, after ignition 

 in vacua, should contain less ferrous oxide than 

 it did originally ; the difference between the 

 quantities of ferrous oxide before and after 

 heating should be equivalent to the hydrogen 

 and carbon monoxide evolved ; and these may 

 be calculated from the equations written above. 



One c.c. of hydrogen or carbon monoxide is 

 equivalent to 0-006428 gram of ferous oxide. 



In order to prove this experimentally, I 

 selected a chlorite from Zoptan in Moravia. 

 This mineral contained 10'60 per cent, of 

 ferrous oxide, 4'79 per cent, of water, and con- 

 sequently gave a considerable quantity of hy- 

 drogen on heating. It was also quite free from 

 sulphides, which seriously interfere with the 

 accurate estimation of ferrous oxide. 



A weighed quantity, about 10 grams, of the 

 chlorite was heated in a hard glass tube till it- 

 ceased to give any gas. The gas was collected 

 and analysed, and the loss of weight of the 

 mineral was determined, by weighing the hard 

 glass tube before and after heating. 



Analysis of gas expressed in cubic centi- 

 metres per gram 



CO., 0-123 



CO" 0-094 



Ho 2-180 



Loss of weight on heating, 4*79 per cent. 



The mineral was allowed to cool in vacua to 

 prevent the oxidation of the ferrous oxide. The 

 ferrous oxide was estimated in a sample of the 

 mineral before and after heating. 



Ferrous oxide in mineral before heating 



(a) 10-62 per cent. ; (b) 10-60 per cent. ; 

 mean, 10'61 per cent. 



Ferrous oxide in mineral after heating 



(a) 9-70 per cent, ; (b) 9-61 per cent. ; 

 mean, 9 '65 per cent. 



But since the mineral lost weight to the extent of 4-79 per cent, on 

 heating, a correction must be applied. 



