250 Robert Warington on the 



On the Production of Boracic Acid and Ammonia by Vol- 

 canic Action. By Robert Warington, F.C.S. 



The simultaneous occurrence of boracic acid and ammonia 

 in the neighbourhood of volcanoes has been frequently ob- 

 served, and its cause has given rise to a good deal of specula- 

 tion, although no very definite conclusions have as yet been 

 arrived at. Some information and specimens I have received 

 from a friend who visited the Island of Vulcano, which is si- 

 tuated about 12 miles north of Sicily, have enabled me to 

 make a few experiments, which, though not so complete as I 

 could have wished, appear to throw some light upon this point. 

 My friend supplies the following information : — " The height 

 of the volcanic mountain is estimated at about 2000 feet, and its 

 crater is about 700 feet deep. The area at the bottom, which 

 may be about 10 acres in extent, is covered with small, loose 

 pieces of limestone, just as though it had been macadamized, 

 and the ground is so hot as rapidly to destroy the leather of 

 the shoes. On thrusting a thermometer between the stones, 

 it indicated, at different points, temperatures varying from 

 250° to 500° Fahr. On looking over this area from the top 

 of the crater, one side of it appeared as if covered over with 

 beautifully-white drifted snow. On reaching the spot, how- 

 ever, this white appearance was found to be caused by a de- 

 posit of finely-crystallized boracic acid. On removing this 

 incrustation, which formed a layer of about an inch in thick- 

 ness, and digging with a pick-axe, there spumed up a mass of 

 red-hot fused lava, similar in appearance to the slag of a 

 glass-house ; this consists of fused saline matters in cohesion 

 with volcanic debris. In other parts of the crater there are 

 holes like foxes' holes, from which blue jets of volcanic flame 

 are issuing continually, and a deposition of sulphur occurs all 

 around. 



" The boracic acid rises in vapour, and condenses on the 

 surface of the ground at the bottom of the crater like a light 

 drifted snow ; and when gathered up, the surface becomes co- 

 vered again with sublimed acid in two or three days. To 

 ascertain this point more decidedly, some hogshead casks, 



