422 K A. Per ret— Vesu 



imis. 



and by September 3 this had increased to 435°. These fuma- 

 roles are acid and water vapor is present in small quantity, but 

 the high temperature causes its absorption by the atmosphere 

 without condensation. In March of 1909 I found 420°, but 

 the pyrometer could not then be introduced at the same point 

 owing to changes in the fumarole. On June 6 I found 428°, 

 and on June 14, 438°, which is the highest I have observed. 

 At this time the fumarole was spoiled for observation, as 

 described above, and on July 9 the temperature was 430°, and 

 on July 19 it was 416° — a progressive decrease due to the 

 choking of the vent. This has begun to clear itself, however, 

 and the temperature has since risen above 420°. I have com- 

 menced observations at another opening, which showed on 

 July 9, 300° and on August 14, 308°. 



The result of these observations shows that if the tempera- 

 tures in this locality have not recently increased to any great 

 extent, they are, at all events, not diminishing, and it is inter- 

 esting and somewhat impressive to see, on this sleeping vol- 

 cano, gases issuing quietly and almost invisibly at temperatures 

 above the melting point of lead. 



Before the destruction of this fumarole it had enlarged 

 itself into the form of a grotto, at one end of which there 

 could be seen an abundant incrustation of a white substance, 

 evidently consisting of alkaline chlorides, but which were not 

 of very recent formation. It is here that we most feel the 

 lack of comparative chemical analyses made at regular inter- 

 vals of time, but through the kind cooperation of Dr. Martin 

 Henze, of the Zoological Station of Naples, I have, at last, 

 been enabled to commence a series of investigations along this 

 line. Gases and deposits were collected here on July 1, 1909, 

 and the analyses, as made by Dr. Henze, are given herewith : 



Water vapor (in small amount) ) -^ . , , ^ ,, • . 

 tt j i.i • -j r -Detected on the spot. 



Hydrochloric acid j r 



Analysis of gas : 



Oxygen 18*3 to 18*7 per cent. 



Nitrogen 81*7 to 81'6 " " 



100-0 100-0 

 Analysis of deposit : 



White substance, soluble in watei\ 



Bases : Na, K, Mg with traces of Al, Ca 

 Acids : HC1, H 2 S0 4 a little, HF1 traces 



Proportion of the substances is in the order given. 



