A FURTHER NOTE ON OBSIDIAN 

 BUTTONS. 



By T. StephexNS, Esq., M.A., F.G.S. 



-♦^ 



The occurrence in Tasmania of these singular spheroids 

 of jet black obsidian, popularly known as "buttons," was 

 brought under the notice of the Royal Society in 1897, 

 by Messrs. Twelvetrees and Petterd,* who gave a very 

 full description of the specimens which had come under 

 their observation, and discussed the various theories 

 which have been put forward to account for their origin 

 and distribution. Tn the same year I contributed a few 

 supplementary remarks on the subject f with special 

 reference to the earliest records of the discovery of these 

 "buttons" in Australia and Tasmania. In 1898, during 

 a journey from Texas, U.S.A., to San Francisco, I had 

 noted the presence of obsidian in lava-flows of Northern 

 Mexico, and had seen some extensive tracts of com- 

 paratively recent volcanic rock in Southern California, 

 which suggested the possibility of our obtaining from 

 that source further evidence respecting these singular 

 volcanic products. Shortly after my return to Tasmania, 

 I sent copies of the abovementioned papers to Dr. Joseph 

 LeConte, the well known Professor of Geology in the 

 University of California, in the hope that his intimate 

 knowledge of the geological conditions of the United 

 States might enable him to throw fresh light on this very 

 obscure subject. 



The occurrence of obsidian in the peculiar form under 

 consideration does not appear to have been noted in 

 California, but Professor LeConte kindly replied to my 



* On the occurrence of obsidian '•buttons" in Tasmania, by W. H. 

 Twelvetrees, F.G.S., and W. F. Petterd, C.M.Z.S. Proe. Royal 

 Society of Tasmania, 1897, p. 39. 



t Remarks on obsidian " buttons," by T. Stephens, M.A., F.Q.S. Pro. 

 Roy. Soc. of Tasmania, 1897, p. 54. 



