39 



217 



the immediate vicinity of the bottles, the standing of the barometer and the 

 exact time. 



The samples of gas for the quantitative analysis were collected in the same 

 way, in bottles (Fig. 8 ß) containing about 150 ccm. These bottles were of a similar 

 shape to those containing the gas to be examined for radioactivity, but the tubes 

 had no stop-cocks, being closed by melting. The samples taken to determine 

 inactive gases contained in the spring gas were at first collected in the sheet iron 

 vessel B in Fig. 9. The volume of the vessel was about 5000 ccm., and the collec- 

 tion of the gas was performed in the usual way. The vessel was then bi ought 

 to the tent, where the sulphuretted hydrogen, the carbon dioxide, the oxygt a and 

 hydrogen were for the most part withdrawn „ 



from the spring gas. The arrangement of 

 the apparatus is shown in Fig. 9. The 

 circuit P, F, M, 0, C, K consists of the Prytz 

 pump '- P, the collecting bottle F, the glass 

 tubes M, and C containing respectively 

 peroxide of manganese, oxide of copper, 

 and metallic copper filings, and the absorp- 

 tion bottle K containing hydroxide of potas- 

 sium to absorb the carbon dioxide. The 

 vessel B, containing the spring gas, is 

 attached to the circuit by means of the 

 T-tube between F and M, while the lower 

 end of the vessel B is connected by an 

 indiarubber tube to the water reservoir N. 

 By lifting N to the necessary height, the 

 gas in B was continually submitted to a 

 slightly greater pressure than that of the 

 atmospheric air. The gas in the circuit 

 could find an outlet through the T-tube T 

 inserted between the pump and the collecting bottle. 



We began operations by filling the collecting bottle, F, with water, and then 

 closing it by clipping the two indiarubber tubes forming the inlet and outlet of 

 the bottle. Keeping the T-tube T open, we pumped out the rest of the circuit by 

 means of the Prytz pump, and washed it out a few times by refilling it with gas 

 from the vessel and pumping it out again with the pump. Finally this part of the 

 circuit was filled with spring gas up to the pump. The clips over the entrance 

 tubes of the bottle F were then unscrewed and the bottle being in a slanting 

 position, the water ran out of it through T, the bottle being filled at the same 

 time with spring gas from the vessel B. As soon as the bottle is full of spring 

 gas, the tube T and the connecting tube between the vessel B and the circuit are 



' K. Phvtz: Zeitschr. f. Instrumentenkunde. 1905, p. 193. 



Fig. 9. 



