14 THE CANADIAN NATURALIST. [Vol. X. 



or 1'65 times the volume of the quartz. From No. 2, 7-20 cubic 

 centimeters of gas were obtained, or 0*97 times the volume of 

 the material employed. From the first portion examined in the 

 preliminary work 1-33 volumes were obtained. 



The eudiometer having been transferred to the mercury cistern 

 an absorption pellet moistened with the solution of potassic hyd- 

 rate was introduced into it, causing a rapid diminution of the 

 volume of the gas. When this operation was complete the resi- 

 dual gas had been reduced to a small bubble in the top of the 

 tube, which could not be measured directly with sufficient accur- 

 acy. To find its volume a little of the potash solution or of 

 distilled water was admitted o-ivins: a meniscus concave toward 

 the top of the tube. The position of this was carefully noted, 

 and the tube emptied. Mercury was now introduced until the 

 surface of the meniscus occupied exactly the former position of 

 the surface of the water, and the metal was then weighed. The 

 mean of five separate measurements being taken the volume of 

 the gas was thus readily calculated. The results of the determi- 

 nations with the two difi'erent portions of the material gave 



100-00 100-00 100-00 



Cuprous chloride produced no preceptible absorption, showing 

 the absence of carbonic oxide. Potassium pyrogallate introduced 

 into the tube with caustic potash solution produced a slight dis- 

 coloration of the latter, but no change in the volume of the gas 

 was visible, indicating that oxygen if present was not in recogniz- 

 able quantity. 



To ascertain the presence of hydrogen or other combustible 

 gases a number of tests were made. A spark passed through the 

 gas directly produced no efi'ect, nor upon the addition of oxygen 

 or air alone could any combustion be produced. When the 

 proper quantity of pure electrolytic gas was added the explosion 

 produced no apparent change in the volume. This, if, from 

 the small amount of gaseous substances operated with, it might 

 not safely be concluded that the hydrogen or hydrocarbons 

 were entirely absent, shows that the quantity was exceedingly 

 small. The residual substance then was nitroo'en. In these 

 operations, as already mentioned, the gas had passed through a 

 tube placed in a freezing mixture. A later experiment, to be 



