Akt. XV. — Coorongite, a South Australian Elaterite. 



By ALEX. C. GUMMING. 



(Communicated by Professor Orme Masson, D.Sc). 



[Eead 9th October, 1902.] 



The name Coorongite was given many years ago to a peculiar 

 substance found as a thin superficial deposit on the soil in the 

 Coorong district of South Australia. A small sample was 

 recently sent to the Chemical Laboratory of the University of 

 Melbourne, and has been examined by me, under Professor 

 Masson's direction, with results to be described in the sequel. 



Previous Accounts. — Coorongite is briefly described by Krause- 

 (Mineralogy, p. 138), and by G. C. Morris (Proc. Acad. Nat. Sci. 

 Philadelphia, 131, 1877), and references have been found else- 

 where ; but by far the best and fullest account of it that I have 

 been able to find is contained in a paper by J. R. Jackson, 

 published in the Pharmaceutical Journal of 1872 (pp. 763 and 

 785). From this paper it appears that Coorongite had, since its 

 discovery in 1865, excited a good deal of interest both in 

 Australia and in England, and that the question of its true 

 nature and probable origin had been the subject of considerable 

 discussion. Very different views were expressed, some regarding 

 the substance as a bituminous hydrocarbon mineral, others 

 believing it to be of vegetable origin. These discussions of thirty 

 years ago appear to have been forgotten, and within the last year 

 attention has been directed afresh to the same questions, still 

 unsettled, by newspaper accounts of quests for mineral oil in the 

 district where Coorongite occurs. Jackson's paper was not 

 known to me till after I had done the work to be described. My 

 results are, in the main, corroborative of those he records and 

 quotes from other observers, but additional information has been 

 gained as to the chemical nature of the material. 



Description of Coorongite. — My specimens were in sheets varying 

 from one-tenth to one centimetre in thickness. The substance 

 varied in colour on the surface from greyish-black to black, but 



