WATER AND VOLCANIC ACTIVITY DAY AND SHEPHERD. 293 



It is not improbable that most of the alkalies, lime, and almnina 

 have resulted from the action of the acid liquid on the glass tubing, 

 but it is of the greatest importance to establish the fact that the en- 

 tire quantity of gas pumped through the "wash bottle" yielded no 

 more than 0.4 gram of chlorine. If this be calculated in the form of 

 gas, it Avill correspond at most to 0.02 per cent, assiuning that ap- 

 proximately 1,000 liters of gas were drawn into the tubes. Fluorine 

 seems to be present in about twice this quantity, but in no sense can 

 these halogens be regarded as forming more than a very minor part 

 of the crater exhalation. 



RARE GASES. 



In the progress of the analyses, after all the active gases had been 

 removed from the several tubes analyzed, there remained an inactive 

 residue which, of course, consisted mainly of nitrogen, but which 

 might be supposed to contain traces of argon, helium, or other of the 

 rare inert gases, should any such chance to have been present in the 

 >'olcano emanation. For the determination or detection of these sev- 

 eral of the residues were brought together in a spark tube and ex- 

 posed for several hours, in the presence of oxygen, to an alternating- 

 current spark discharge of considerable intensity. A^Tien the volume 

 of residual gas could no longer be diminished by this means, there 

 remained a final residue of 75 cubic centimeters of gas, which was 

 forwarded to Prof. R. W. Wood, of Johns Hopkins, who very kindly 

 offered^ to make a spectroscopic examination of it for traces of the 

 rare gases. The search yielded a decisive negative result. Xo lines 

 characteristic of any of the rare gases could be found with the 

 spectroscope, nor did exposure to charcoal at the temperature of 

 liquid air leave any residue whatever. The gas examined was, there- 

 fore, all nitrogen. Subsequently the residues (15 cubic centimeters) 

 from another group of the tubes were treated in the same way and 

 forwarded to Prof. Wood, who was again able to detect nothing but 

 pure nitrogen. It appears to be definitely established, therefore, that 

 the gases collected from Halemaumau in May contain nitrogen but 

 no argon. This affords a most desirable confirmation of our belief 

 that the volcano gases were successfully collected before they had 

 come in contact with atmospheric air at all, and were therefore en- 

 tirely uncontaminated either by reaction or admixture with it. It 

 also offers support to the view that the volcanic nitrogen is not of 

 atmospheric origin — to which further allusion will be made in the 

 concluding paragraphs. 



1 We desire to take this opportunity to thank Prof. Wood for courteously offering to 

 examine these gas residues. The Geophysical Laboratory at Washington possesses 

 neither the equipment nor the special experience necessary to undertake a spectroscopic 

 study of this critical character. 



