144 



KECORDb OF THE AUSI KALIAN UlUSEUM. 



Composition. The metliod 'of analysis is tliat described by 

 Gooch^^ with modifications suggested by Penfield and Speriy,'* 

 boric anhydride being distilled with alcohol, caught in strong 

 ammonia solution, transferred to a basin and evaporated over 

 lime as described in a former paper.'^ For this determination 

 1-1478 gram was fused with sodium carbonate, exhausted with 

 water, filtered, the filtrate acidified with nitric acid and distilled. 

 Water was determined directly in a Penfield tube on -6108 gram 

 mixed with previously ignited lime to minimise the risk of 

 expelling boric anhydride. The other constituents were esti- 

 mated in another portion weighing about a gram. The result of 

 analysis is appended (I) together with an analysis by Whitfield^' 

 of datolite from Bergen Hill, New Jersey (II). 



In conclusion I have to acknowledge my indebtedness to 

 Messrs. W. F. Petterd and D. A. Porter, for "the loan of speci- 

 mens and for much valuable information, and to Professor T. W. 

 ej. David, B.A., Trustee, for permission to use the goniometer in 

 the Geological Department of the University of Sydney. 



13 Gooch— Bull. U.S. Geol. Survey, No. 42, 1882, p. 64 



'* Penfield and Sperry— Am. Journ. Sci., (3), xxxiv., 1887, )5. 222. 



'5 Ander,-on— Rec. Austr. Mus., v., 1904, p. 128. 



^" Wliitfield^Bull. U.S. Geol. Survey, No. 55, 1889, p. 59. 



