Jay gar — Yolcanoloyic Investigations at Kllauea. 167 



Carbon monoxide 2 



Hydrogen 3 



Sulphur _ __ 2 



Nitrogen . __ 14 



These are in two groups of three each, namely carbon mon- 

 oxide, hydrogen, and sulphur, all inflammable, and the three 

 products of the combustion or oxidizing of these, namely car- 

 bon dioxide, water vapor, and sulphur dioxide. The only 

 other abundant ingredient is nitrogen (14 per cent), which is a 

 constituent of air. 



The lava was splashing within the glowing spatter cupola 

 whence the gas was drawn. This lava was below the level of 

 a porous "shattered floor" made of lava shells. A channel 

 " just below the surface crust " connected this pot with the 

 lake directly. The roof of this channel collapsed to a chasm a 

 few days after the gases were collected. "As the larger bub- 

 bles rose and burst from the liquid lava within the dome, the 

 jar could be felt on the floor where the collectors stood and a 

 splash could be plainly seen through the cracks."* In other 

 words, YQi:j hot gas only 7 per cent of which was combustible 

 and 79 per cent of which was a combustion product, was rush- 

 ino; out throuo^h the cracks of the dome above the level of a 

 tunnel leading to the open, cooler air above the lake and all 

 the surrounding floor was porous shattered rock shells full of 

 air above the liquid level and doubtless communicating through 

 scores of openings with the tunnel and the dome which throbbed 

 and jarred. And in addition, the lake, consisting of the same 

 gas-charo^ed lava as that in the dome, was incessantly engulfing 

 air-fllled crusts and skins and doing so with especial vehemence, 

 by streaming in the direction of this grotto channel, and thereby 

 also pumping air through the tunnel. 



Under these circumstances it is impossible for the writer to 

 conceive of the 79 per cent of oxidized gas as having had no 

 contact with air before emerging from the blowing cone. 

 There is no question but that this was the most perfect experi- 

 mental collection of volcanic gas ever made, but I do not believe 

 that any apparatus at the surface of the volcano can collect 

 uncontaminated juvenile gas. The writer does not wish to be 

 understood to imply that all the oxygen compounds in the gas 

 are atmospheric combustion products, but that a larger propor- 

 tion of them are so than these authors have admitted. The 

 facts demonstrated, however, by the Day and Shepherd collec- 

 tion, of the presence of the three combustibles and the three 

 combustion products, and the argument which they present of 

 heat reactions that reach a maximum at the surface, make a 

 contribution to volcanoiogy which bids fair to revolutionize 

 the science. 



*Loc. cit., p. 588. 



