218 40 



closed. By pumping the gas in the circuit in the direction shown by the arrow, 

 the sulphuretted hydrogen and the carbon dioxide are absorbed. The gases absorbed 

 in the circuit are soon replaced by fresh spiùng gases introduced by opening the 

 tube connecting the vessel with the circuit. 



When the continued circulation of the gas does not further reduce the pressure 

 in the circuit, showing that the absorption of the sulphuretted hydrogen and the 

 carbon dioxide is nearly completed, the oxide of copper and the copper filings are 

 heated, in order to destroy the free hydrogen and oxygen. When the spring gas 

 contained carbon dioxide in exceptional quantities, it might happen that the caustic 

 potash in the absorption flask K would not be sufficient to absorb the carbonic 

 acid gas completely. Then the used solution of caustic potash was removed from 

 K, by compressing a little of the gas above the solution, and then opening the 

 stop-cock h. When the solution had mostly run out, the stop-cock was turned off. 

 A fresh solution of caustic potash was then sucked into K by reducing the pressure 

 in the flask. 



After having in this way freed the gas in the circuit of its contents of 

 sulphuretted hydrogen, carbon dioxide, oxygen, Iiydrogen and other combustible 

 gases, the pressure in the collecting bottle was reduced a little, and the bottle 

 closed by melting. The volume of the bottles used to collect these gas samples 

 was 500—800 ccm. 



After the journey the sealed bottles were brought to the Physical Laboratory 

 of the Polytechnic Academy, Copenhagen, where I undertook a closer examination 

 of the gases contained in the bottles. Of course, this investigation naturally came 

 under two heads, viz. an ordinary quantitative analysis of the gases contained in 

 the bottles of 150 ccm.; and an attempt to trace and partly to determine the 

 amount of the rare inactive gases collected in the larger bottles containing 

 500—800 ccm. 



3. Analysis of the gases. 



In the quantitative analysis I aimed at a determination of the relation between 

 the following gases contained in the spring gas : sulphuretted hydrogen, carbon 

 dioxide, oxygen, hydrogen, methane, and nitrogen, plus the inactive gases. 



In the analysis work 1 employed a Pettersson analysis apparatus from the 

 firm of Franz Müller (Dr. H. Geislers Nachf) Bonn a/R. 



The measuring tube contained 35 ccm., and the smallest divisions corresponded 

 to j*g ccm. so that I could with considerable accuracy read ^^ ccm. In connection 

 with this apparatus 1 used absorption pipettes for absorbing sulphuretted hydrogen, 

 carbon dioxide, and oxygen, and an explosion pipette. 



To transport the gas to be examined conveniently and safely from the col- 

 lecting bottle to the measuring tube, I proceeded in the following way: The end of 

 the sealed tube of the collecting bottle was knocked ofl" while held under the sur- 

 face of mercury, and a short indiarubber tube, which could be closed by a clip 



