55 



247. These results are sufficient to determine the class and 

 name, and there can be little doubt that this determination 

 will be corroborated by analysis and microscopical examina- 

 tion. 



Another form of the same substance, from the volcano of 

 Kilanea, in the Sandwich Islands, and known as " Pele's 

 hair," is exhibited for comparison. This condition is pro- 

 duced by jets of liquid lava coming in contact with strong 

 gusts of wind, which instantly cool them, and carry the pro- 

 duct away in the form of spun glass. 



Obsidian Buttons. 



As a supplement to the valuable paper contributed by 

 Messrs. W. H. Twelvetrees, F.G.S., and W. F. Petterd, 

 C.M.Z.S., on the subject of obsidian "buttons," the following 

 particulars of the history of their occurrence in Australia may 

 be of some interest : — 



In Darwin's Geological Observations on the Volcanic 

 Islands visited during the voyage of H.M.S. Beagle, 1832- 

 1836, mention is made of a "volcanic bomb " found in the 

 interior of Australia, and presented to him by Sir Thomas 

 Mitchell. Incidental reference is made to this circumstance 

 by various writers, but unfortunately there is no copy of the 

 original work, either in the Library of the Royal Society, or 

 in the Public Library, so that no quotations can be given 

 from the actual observations of the distinguished author. 

 In a paper read before the Geological Society in 1855,* ten 

 years after the publication of Darwiu's book, the Rev. W. B. 

 Clarke refers to Darwin's description of " a volcanic bomb of 

 green obsidian, from the plain between the Rivers Darling 

 and Murray," and cites several instances of the discovery of 

 similar specimens which had recently come under his own 

 observations. Mr. Clarke says : — " Sir T. L. Mitchell's 

 specimen would seem either to have drifted from a very long 

 distance, or, which is more likely, from the known habits of 

 the aboriginals, to have been dropped by one of them, who 

 probably found it in the trap-hills of the Lachlan, to the 

 north-eastward. This specimen was unique in Australia 

 until recently. 



"During the last two years several similar specimens have 

 been found in the auriferous detritus of the western and 

 northern gold-fields. 



" The first which I met with was found in the cradle of a 

 gold- washer on the Turon River, who dug it from a depth of 30 

 feet below the surface. This w r as a small, irregular, roundish 



* "On the Occurrence of Obsidian Bombs in the Auriferous Alluvia of New 

 South Wales. By the Rev. W. B. Clarke, M.A., F.G.S."— Quarterly Journal of the 

 Geographical Society, March, 1835. 



