322 Kenneth A. Mielde: 



cylinder A. The capillary tube C enters the reservoir F through 

 the base, and rises to a point about level with the bottom of the 

 enlarofed diameter of the reservoir at F. 



The sample of gas collected from the Toepler pump over 

 mercury in a small test tube is introduced by inserting 

 the test tube over the end of the capillary at F, which is 

 under mercury. The test tube is pushed down until the end 

 of the capillary is in the gas above the mercury. The gas i? 

 then drawn into the capillary by working the hand wheel E. 

 The volume of gas is measured on the scale of the capillary 

 tube C. This tube is divided into 60 divisions, subdivided into 

 tenths. Sixty divisions on the scale = 0.2 c.c. The absorbing 

 reagent, such as caustic potash or alkaline pyrogallol, is intro- 

 duced in the same manner as the sample of gas, and is brought 

 into contact with the latter by turning the small wheel until 

 the liquid reaches the bulb B, after allowing time for the 

 absorption to take place, the gas is pushed back by the mer- 

 cury and the piston, and the volume again read, the diminu- 

 tion, if any, being noted, D is a screw tap to withdraw the 

 mercury from F. 



The results of these tests and analyses show that from the 

 sulphides and material containing sulphides, such as the Broken 

 Hill tailings and slimes, as a rule more gas was obtained than 

 from the calcite and quartz. This gas consisted mainly of car- 

 bon dioxide. The residual gas, after absorbing the carbon 

 dioxide and oxygen, was largely in excess of the proportion of 

 nitrogen in atmospheric air, and may contain hydrogen or an 

 excess of arofon. That the carbon dioxide in these tests is not 



