14$ J. W. Shipley — Volcanic Emanations in Alaska. 



sample was extracted successively with the following sol- 

 vents nntil no further extract from each was obtained. 

 The solvents in the order used were : ether, petroleum 

 ether, carbon disulphide, benzene, carbon tetra-chloride, 

 ethyl alcohol and glacial acetic acid. Each of the sol- 

 vents extracted organic matter varying in amount from 

 half a gram to a centigram, CS 2 and (C 2 H 5 ) 2 being the 

 most effective. Several of the solvents extracted con- 

 siderable quantities of free sulphur. On evaporation, 

 a brownish-black resinous mass was left by each solvent. 

 None of the extracts belonged to the aliphatic series, 

 none contained nitrogen and none were unsaturated. 



Steam distillation carried over the organic matter to- 

 gether with the free sulphur, and the first portion of the 

 distillate gave an unmistakable odor of naphthalene. 



The occurrence of this deposit of aromatic hydrocar- 

 bons may have some significance in the theory of volcanic 

 origin for such compounds. The deposit lies close to the 

 most active area of the district and is associated with 

 NH 4 C1 and sulphur, while H 2 S is unusually concentrated 

 in the escaping gases. On the other hand they might 

 equally well be attributed to steam distillation from the 

 sedimentary rocks with subsequent condensation in the 

 ash on the surface. The Jurassic sandstones meet 

 the igneous intrusion in the immediate neighborhood. 



Surface Temperatures. — The normal temperature for 

 the volcanic ash in the month of July was between 10° 

 and 12 °C at a depth of four inches. Owing to there be- 

 ing considerable areas over which the activity seemed to 

 be general rather than confined to a narrow vent or fis- 

 sure, the temperature of the mud flow was taken at 

 numerous places. Temperatures above 10°-12° were ab- 

 normal and indicated hot gases permeating the mass of 

 the flow. The temperatures recorded varied from 10° 

 to 100° C, higher temperatures than 100° only being found 

 in the open vents or cracks but hot vents and fissures were 

 frequently surrounded by areas covered with blue mud 

 the temperature of which approximated 100°. This blue 

 mud was a mixed layer of ash and the phosphate of iron 

 already described, saturated with water to a depth of 

 four to eight inches. Such an area of hot vents and 

 viscous blue mud covering at least frve acres occurs about 

 five miles down the valley from Novarupta volcano. 

 This area is quite fluid beneath the brown crust covering 

 the mud. 



