BY W, F. PETTERD, C.M.Z.S. 127 



where a portion of this lot is still on exhibition. They are 

 known as ' Emu stones " in the north-western portion of 

 Australia, and about Kalgoorlie and Coolgardie the natives 

 attribute medicinal properties to them. 



Specimens from all the States of the Commonwealth, 

 except Queensland, have been catalogued, with the result 

 that a remarkable conformity is apparent, which distinctly 

 suggests a common origin. The analysis further shows 

 that' they are practically distinct from all known acid 

 rocks, and that they are certainly not of artificial origin. 

 It is also certain that they have no connection with any 

 knovrn volcanic rocks, as those of the Tertiary epoch, so 

 far as known, are all of basic composition. As a rule, they 

 show a remarkable similarity as regards surface abrasion, 

 although in rare instances some specimens appear per- 

 fectly fresh, as if they had been recently cast in a mould, 

 in which case they have in all probability been thus pre- 

 served in a yielding clay or other soft substance. 



Apparently they were first referred to by Charles Dar- 

 win, in his " Geological Observations on Coral Eeefs," 

 1851. The specimen therein described was given to him by 

 Sir Thomas Mitchell. It was found at a locality between 

 the Rivers Darling and Murray, and was of the discoidal 

 form. Since that time various authors have written 

 respecting these mysterious objects, and diverse theories 

 have been formulated to explain their distribution and 

 origin. Some of tliese theories are unreasonable, and only 

 remarkable for their originality. One writer (Mr. W. H. 

 Twelvetrees, '' Record of Obsidianites in Obsidian Buttons 

 in Tasmania," Pro. Roy. Soc. Tas., 1905) states, '■ How 

 difficult it is for geologists at a distance to appreciate the 

 mode of occurrence," and, it might be added, to also appre- 

 ciate a reasonable theory as to their origin. 



Amid the various writers on the subject the beautifully 

 illustrated thesis by Dr. Franz E. Suess, of Vienna (Die 

 Herkunft der Moldavite und Verwandter Glaser Wien, 

 1900), stands out prominently for its careful and laborious 

 investigation and elaborate detail. Dr. Suess brings strong 

 evidence to show that there is no reasonable doubt that 

 these objects are of cosmic origin; and the same applies 

 with equal force to two other known occurrences of a simi- 

 lar character, viz., that of the well-known bouteiilenstein 

 of Bohemia, and that described by Dr. R. D. W. Verbeck, 

 from the island of Billiton, in the Malay Archipelago, all 

 of which are confined to Quarternary shallow alluvial 

 •deposits. 



