Reviews — Manganese Ores. 279 



discussion of the chemistry and physics of water, by Dr. R. Kremann, 

 of Graz, with title-page and index of vol. iii, first half ; part vii 

 commences the second half of vol. iii with the mineralogy of Uthimn, 

 sodimn, potassimii, native copper and copper oxides, rubidium, and 

 silver, also chiefly written by Dr. Leitmeier. 



We are glad that it has been found possible to continue publica- 

 tion of this monumental work, which is of the greatest value from 

 the amount of detailed information contained in it, as well as for the 

 numerous references to the literature of modern mineralogy. 



Manganese Ores. By A. H. Curtis. Imperial Institute Mono- 

 graphs on Mineral Resources, pp. 118. 1919. Price 3,s-. Qd. net. 

 T^HIS is an Imperial Institute publication which reflects credit 

 -*- on the author, who has prepared an interesting and useful 

 monograph, as a result of an exhaustive study of all published 

 information on the subject. 



The War focussed attention on manganese ores, as the principal 

 consumers drew their supplies from India, Caucasia, and Brazil, 

 which necessitated ocean transport ; and also because efforts to 

 find an efficient substitute for manganese in the manufacture of 

 steel were only partly successful. 



Notwithstanding the high selling value of the mineral in recent 

 years, few new dejDosits have been discovered. In Brazil, where 

 the price incentive w^as perhaps greater than elsewhere, only one 

 large ore body was found, which even now is not producing. In 

 India no new developments have taken place, but the ferruginous 

 deposits of the Sinai Peninsula, and those of the Gold Coast, both 

 discovered shortly before the War, are now active producers. 



The most striking development in the industry since 1914 took 

 place in the United States, which not only intensively operated its 

 own low-grade deposits, but also manufactured practically all its 

 manganese-iron alloys, which in pre-War days had been largely 

 imported from Euroj)e, either in blast furnaces or by electric 

 reduction. 



In chapter I the author deals with the occurrence, character, 

 and uses of manganese. It should be mentioned that the large 

 Belgian imports of manganese ore prior to 1914 were principally 

 used in Luxemburg and Germany. Further, the high manganese 

 content of Caucasian mineral refers to the product of washing 

 plants, which constitutes two-thirds of the total output, the " run 

 of mine " being of inferior grade to the Brazilian and Indian ores 

 which are not dressed. 



It is interesting to record that the inability of the Caucasus and 

 Brazil to increase their output in f)re-War years was almost entirely 

 due to the railways, on which the mineral was carried, being State- 

 owned and operated, although in Russia there has always been the 

 added disability due to labour unrest. 



