6 



THE GASES IN ROCKS. 



the most abundant gas, carbon dioxide is the most characteristic con- 

 stituent of the latter. His analyses are given in table 1. 



TABLE 1. 



This table shows that in the iron meteorites carbon dioxide in no case 

 constituted more than 15 per cent of the gas evolved, while in every case 

 but one the quantity of carbon monoxide was considerably greater. In 

 the stony meteorites carbon monoxide is low, while carbon dioxide is, in 

 the majority of analyses, much the most abundant gas. Hydrogen is more 

 important in the iron meteorites than in the stony. 



The same experimenter determined also the gases given off by the same 

 meteorite at different temperatures. His figures for the Iowa County 

 meteorite are shown in table 2. 



TABLE 2. 



The progressive decrease in the percentage of carbon dioxide and the 

 corresponding increase of hydrogen with the elevation of the temperature 

 are striking. His inquiries into other phases of the problem will be deferred 

 until the discussion of principles, where it will be possible to treat each 

 factor to better advantage, in its proper relation to the whole subject. 



Several years later Wright applied his method of gas extraction and 

 reliable quantitative analysis to the gases in smoky quartz, 1 which here- 

 tofore had been subjected chiefly to qualitative microscopical studies- 

 However, only one determination was made that of a costal from 

 Branchville, Connecticut, which yielded a small quantity of gas of the 

 following composition: Carbon dioxide, 98.33; nitrogen, 1.67; hydrogen 

 sulphide, sulphur dioxide, ammonia, fluorine, and chlorine, trace. 



1 Wright, Am. Jour. Science, vol. 21 (1881), pp. 209-216. 



