24 



abstracts: volcanology 



rather unusual difficulties in the matter of collection and also in the 

 analysis. 



This preliminary report is concerned primarily with the 19 17 col- 

 lection, but includes a new analysis of one of the 191 2 tubes and one 

 tube from Jaggar's 191 8-19 collection, for comparison. From an ex- 

 amination of the tables of analyses it appears that the gases from this 

 volcano varj^ greatly in composition. About the only constituent 

 which appears in more or less constant quantity is water vapor, which 

 averages about 50 per cent of the gases given off by the lava. This 

 refers, of course, to the gases obtained from the inside of flames, i. e., 

 before the gas has come in direct contact with air. The remaining 

 constituents are CO2, CO, H2, No, Ar (trace), SO2, and S2, with 

 traces of CI2 and F2. The chief ingredients are CO2, SO2, S2, and H2O. 

 It seems significant that the combustible gases are (at the surface) 

 relatively small in amount, and this doubtless explains the quiet nature 

 of Kilauea eruptions — there is little left to furnish an explosion. It is 

 also probable that with the additional evidence which the gases re- 

 cently collected by Jaggar and the systematic collection which he pur- 

 poses for the future will furnish, we shall be able to establish the relative 

 importance of the several hypotheses thus far proposed to account for 

 the energy supply of this crater. The analyses of the 191 7 gases are 

 as follows: 



Gases Collected from Kilauea, 19 17 



[Volume per cents at i200°C.] 



Tube 



ii 

 21 



3- 

 4- 

 5- 

 6. 



7- 

 8. 



9- 

 10. 



CO2 



2.65 

 17-95 

 33 48 

 1 1 . 12 



9-54 

 I .97 



17-25 



15-27 



8.32 



1-54 



CO 



I .04 

 0.36 

 I .42 

 3 92 

 I . 12 

 0.82 

 o .62 



0.45 

 0.82 



0.43 



H2 



4 .22 



I -35 

 1.56 

 1.42 



I 53 

 0.21 

 0.76 

 0.70 

 1.82 

 0.37 



N2 



Ar 



udt. 

 udt. 

 0.45 

 0.51 



0.07 

 0.18 

 o. 14 

 0.29 

 0.39 



SO; 



o . 16 



3 51 

 29.83 



9.90 

 0.95 

 9-75 

 6.98 

 16.80 



S: 



0.70 

 0.49 



1 -79 

 8.61 



2 .72 

 2 .70 

 I .07 

 0.49 



2-49 

 3-56 



CI2 



udt. 

 udt. 

 0.17 

 o .02 



0.25 



I .01 



I -34 



H2O 



67 

 38 

 17 

 77 

 64 



89 

 64 



75 

 59 

 89 



99 

 48 

 97 

 50 

 71 

 77 

 18 

 08 

 97 

 93 



^ Tubes I and 2 were analyzed before the calcium tube was added to the apparatus, 

 so that the rare gases were not determined. Chlorine was not determined in these 

 tubes (udt.). Other blanks in the table mean that the gas was not present inde- 

 terminable amounts. K. S. S. 



