Reviews — A. L. dii Toit — Phosphates of Saldanha Bay. 133 



Yery large quantities of sands, crushed rocks, clays, and other similar 

 materials are also employed as what may be called for convenience 

 "refractories" in many industrial processes carried on at high tem- 

 peratures. This subject is dealt with briefly by Professor Boswell. 

 It is known, however, that an investigation on a large scale of British 

 resources of refractories has been carried out by the Geological Survey, 

 and the publication of their results will be awaited with much 

 interest. 



It is apparent that the detailed study of sands, undertaken 

 originally for purely geological purposes, has proved of great practical 

 and economic use, thus affording one more instance, if one were 

 needed, of the ultimate value of pure science for industrial ends, a 

 fact which has long been recognized and acted on in Germany, but 

 which the people of this country are only just beginning to realize. 

 R. H. R. 



II. — Report on the Phosphates of Saldanha Bay. By A. L. 

 DTJ Toit. Memoir 10, Geological Survey of the Union of South 

 Africa, pp. 34, with a map. Pretoria, 1917. Price 2s. 6d. 



rriHE region described in this report lies on the west coast of Cape 

 JL Colony : the country consists of granite, quartz-porphyry, 

 surface limestones, and blown sand. Along the coast are raised 

 beaches. In connexion with these a small quantity of good quality 

 phosphorite has been located, while in addition there are great 

 masses of phosphate of alumina and iron of much less agricultural 

 value. It is hoped that a special method of treatment that has been 

 devised will enable this phosphate to be used as a fertilizer. The 

 origin of the phosphate is interesting. It is due to the percolation 

 of solutions from guano into limestones, shell-beds of the raised 

 beaches, and other detrital deposits. Even boulders and chips of 

 granite and porphyry are more or less phosphatized. The whole 

 phenomenon is compared by the author with Sir J. J. H. Teall's 

 classical description of Clipperton Atoll, where a trachyte has been 

 phosphatized by a similar process. 



R. H. R. 



III. — Report on the Building and Ornamental Stones of Canada. 

 Vol. IV : Provinces of Manitoba, Saskatchewan, and Alberta. By 

 "William A. Parks, pp. xiv-f 333, with 56 plates and 7 drawings 

 and maps. Ottawa: Government Printing Bureau, 1916. 



rilHIS, the fourth, volume of the excellent series of reports on the 

 X building and ornamental stones of Canada which is issued under 

 the auspices of the Canadian Department of Mines, deals with the 

 products of the three provinces of Manitoba, Saskatchewan, and 

 Alberta, and is from the pen of Dr. W. A. Parks. As he states in 

 the letter of transmittal to the Director of the Mines Branch, in the 

 earlier volumes attention was paid only to actual quarries, whereas 

 in the present one the scope has been enlarged so as to include 

 possible sources of supply which have not yet been exploited, and 

 "in consequence of this change of plan the report has reached 



