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XII. — Report 07i the Chemical Qualities and Analysis 

 of a Comhustible Mineral Substance from the Mersey 

 River, Tasmania, forwarded hy Mr. A. M^Naughtan, 

 of Hohart Town. By Professor Penny, of the Ander- 

 sonian University, Glasgow. \_Read 13th Sej)tember, 

 1854.] 



This mineral consists essentially of a mixture of silicious 

 sand and clay, with a combustible fossil substance, re- 

 sembling resin. It also contains small quantities of water 

 and iron pyrites, (sulpliuret of iron). 



One hundred parts gave by analysis the following 

 results : — 



Kesinous matter,.,, 26"64 



Sand and clay 69'83 



Pyrites 3'16 



Water 1-37 



100. 



Under the microscope the leading ingredients may be 

 easily recognized and distinguished. The clay and sand, 

 which are nearly colourless, form the basis, and by far the 

 greater bulk, of the mineral, while the resinous matter, which 

 is of a light amber-brown colour, is disseminated through 

 the clay basis in extremely minute particles or flakes. 



The resinous matter renders the mineral highly combus- 

 tible. ' When heated in the open fire it readily kindles, and 

 burns with a bright voluminous flame, giving off much 



