128 CARNEGIE INSTITUTION OF WASHINGTON. 



It is obvious from a glance at this group of gases that they can 

 not exist together at a temperature of 1000° or more without inter- 

 reaction, and that the reactions are of a kind to produce heat in 

 considerable quantity. Reaction will begin between the gases in 

 the rising lava column the moment pressure has diminished to the 

 point where they begin to be released from solution. As the lava 

 rises to the surface, the pressure upon it diminishes steadily, setting 

 free a continually increasing quantity of gas which is then free to 

 enter into new chemical relations. This chemical activity will be a 

 maximum at the surface at the moment of discharge into the 

 atmosphere. 



It would seem to be a necessary consequence of this mode of 

 release of the gases previously in solution and the resulting exo- 

 thermic reactions between the gases after release, that the tempera- 

 ture of the lava lake should rise when the quantity of gas given off 

 is large, and should diminish again when the gaseous exhalation 

 diminishes in volume, and this was found to hold true throughout 

 the activity of the summer of 1912, of which we were witnesses. 

 The measured changes of temperature in the lava in this interval 

 of about four months (the quantity of lava in the basin remaining 

 practically constant) amounted in maximum to 115°. This repre- 

 sents a total quantity of energy of very large magnitude which has 

 not been reckoned with hitherto in the consideration of the problem 

 of volcanism. 



The much mooted question whether water is an active participant 

 in volcanic activity appears to be answered conclusively in the 

 affirmative so far as Kilauea is concerned. Not only was water 

 actually collected in considerable quantity (300 c.c.) directly from 

 the liquid lava at a temperature of 1000°, but this was done under con- 

 ditions which completely excluded contamination with air. More- 

 over, the presence of free hydrogen associated with CO2 and SO2 

 at this temperature is of itself a sufficient guarantee of the presence 

 of water among the volcanic gases. Indeed, the reaction between 

 H2 and CO2 (the water-gas reaction, H2+CO2 Zll CO + H2O) has 

 long been well known and has been studied in great detail. 



It is of considerable importance to note further that the nitrogen 

 exhaled by the volcano contains no argon. Bearing in mind that 

 argon is always present in the atmosphere in measurable quantities, 

 and that it enters into no chemical combination whatever, it would 

 seem to be a necessary conclusion that the atmosphere does not 

 contribute to the gases given off by the lava. If atmospheric ingre- 

 dients were present in the lava, then surely the argon must be given 

 off again. This must apply to all atmospheric ingredients, including 

 water, whether originally gaseous or condensed; for if meteoric 

 water were to find its way into the lava it must do so as a gas and 



