RECENT ADVANCES IN SCIENCE 215 



differ greatly from ordinary underclays, and appear to have 

 been deposited as fine siliceous muds in still and probably 

 landlocked waters {Trans. Ceramic Soc. 191 7-1 8, 17, 35-56). 



In an article on British supplies of potash felspar, Prof. 

 P. G. H. Boswell summarises the requirements of the pottery 

 and glass industries in respect to this mineral, and also 

 discusses its use for the extraction of potash. A survey of 

 British resources of felspar shows that no large supplies as 

 good as those of Scandinavia are available ; but further 

 exploration, especially in Scotland, should be made (Trans. 

 Soc. Glass Tech. 191 8, 2, 35-71). 



Boswell, P. G. H., A Memoir on British Resources of Sands 

 and Rocks used in Glass-making, with Notes on Certain Crushed 

 Rocks and Refractory Materials. Second Ed., complete in one 

 volume, 191 8, pp. 183 (Longmans and Co.). 



Dr. F. L. Stillwell regards the quartz reefs of the Bendigo 

 goldfield (Vict.) as deposited from ascending aqueous solutions, 

 but the solutions are believed to have been forcibly intruded 

 in the same manner as igneous dykes (The Factors influencing 

 Gold Deposition in the Bendigo Goldfield. Commonwealth of 

 Australia, Advisory Council of Science and Industry, 191 7, Bull. 

 No. 4, pp. 68 ; a summary of this bulletin is to be found in 

 Econ. Geol. 191 8, 13, 100-11). A laminated variety of quartz 

 is very common and frequently carries the most gold. This 

 material is believed to be due to replacement of slate by quartz. 

 A. M. Bateman criticises the above conception of origin (Econ. 

 Geol. 191 8, 13, 222-3), an d points out that if the ore deposits 

 are to be accounted for by forcible intrusion with replacement, 

 they might be expected to occur in almost any part of the 

 folded rocks in which they are found, especially in the sheared 

 limbs of the folds, and not so generally confined as they are 

 to the crests. 



Brown, J. C, Geology and Ore Deposits of the Bawdwin 

 Mines (Burma), Rec. Geol. Surv. India, 191 7, 48, pt. 3, 

 121-78. 



Lindeman, E., and Bolton, L. L., Iron Ore Occurrences in 

 Canada, vol. i. Dept. Mines, Canada, 191 7, pp. 71. 



Imperial Institute, London. Zinc Ores, Monographs on 

 Mineral Resources with Special Reference to those of the British 

 Empire, 191 7, pp. 64. 



