402 



SCIENCE 



[N. e. Vol. LI. No. 1321 



ber of tihe group, ruthenium, came much later, 

 and was made by C. Claus in 1844; it was first 

 announced in Russian, in his essay for the 

 Demidov Prize, published at Kazan in 1844. 



Professor Howe states that the compilation 

 of his first platinum bibliography was probably 

 due to a suggestion made by Dr. H. Carring- 

 ton Bolton, and his special interest in the plat- 

 inum group of metals was aroused by a chance 

 remark of Dr. F. W. Clarke, who expressed 

 surprise the chemists were not more inter- 

 ested in them.'' The series of valuable studies 

 in ruthenium, the least known metal of the 

 group, and the indispensable bibliography, are 

 fruits of thirty-five years of devoted applica- 

 tion to the study of this series of metals. 



The bibliography takes due notice of those 

 indispensable aids to the investigator and stu- 

 dent of the platinum metals, the annual re- 

 ports of " Mineral Resources " by the United 

 States Geological Survey, and those comprised 

 in the year book entitled " Mineral Industry." 

 In the former this subject has been successively 

 treated since 1904, by David T. Day, F. W. 

 Horton, Joseph Stnithers, Waldemar Lind- 

 gren, and for several years past by Dr. J. W. 

 Hill, who has contributed a particularly able 

 study of the platinum deposits of the world to 

 the Engineering and Mining Journal for 1917, 

 Vol. 103, p. 1145. In Mineral Industry, from 

 1892, the reports have been furnished, in suc- 

 cession, by Charles Bullman, Henry Louis, 

 Joseph Struthers, L. Tovey, Frederick W. Hor- 

 ton, F. Lynwood Garrison, and in the years 

 1916-1919 by the writer of the present notice, 

 who also contributed the platinum data for the 

 Eleventh Census (of 1890) with photographs 

 he took while studying the deposits and has 

 published in the Bulletin of the Pan-Amer- 

 ican Union for November, 1917, a paper 

 entitled " Platinum : with especial reference 

 to Latin America " (23 pp., with many 

 illustrations), as well as another paper, in a 

 ,la;ter issue of the Bulletin, on the palladium 

 dejwsits of Brazil. 



A work of this kind makes a special appeal 

 at the present time, when the manifold uses to 



* From a personal communication of Professor 

 Howe's dated February 17, 1920. 



which platinum and the platinum metals can 

 be put, are better known than ever before. The 

 intense demand for the metal in the munition 

 factories, because of its superior resistance to 

 the action of acids, brought it to the notice of 

 many who had barely heard of it in times past. 

 Still the fact that before the war some 500,000 

 ounces of it had already found employment for 

 catalyzing purposes, as much more for elec- 

 trical apparatus, at least 1,000,000 ounces for 

 dental work, and another 1,000,000 ounces for 

 chemical vessels, retorts, crucibles, etc., shows 

 that its peculiar merits were recognized by 

 many. Of late years it had become a favorite 

 metal for gem-setting, more especially for dia- 

 mond-setting, because of the refined beauty of 

 its silvery hue, and its great durability. 

 Another, analogous use, was in the finer ar- 

 ticles of jewelry, wherein more truly artistic 

 efiects could be secured by its employment 

 than by that of gold. 



The gradual increase in value due to these 

 circumstances had already been quite marked 

 before the war. In January, 1909, an ounce 

 of platinum was worth $24.10, only a few dol- 

 lars more than an ounce of gold ($20.67) but 

 by July, 1914, just before the outbreak of the 

 World War its price had risen to $43.50; in- 

 deed it had commanded as much as $46.25 for 

 a brief time in 1911. However, as a result of 

 the special war demand, and of the interrup- 

 tion of the supply from Russia, which had 

 produced annually 90 per cent, of the world's 

 platinum, prices began to soar, until by the 

 early part of 1918 the government set an offi- 

 cial limit of $105 an ounce, and took at that 

 figure the entire imports of the metal as well 

 as part of the stocks on hand. 



The end of the war, and the removal of this 

 price-restriction, coupled with the sale of the 

 stock accumulated by the goverim-ient, brought 

 about, for a vei-y brief time, a trifling reaction 

 to be soon followed by a resumption of the up- 

 ward movement, so that at present, in Feb- 

 ruary, 1920, as much as $165 has been paid 

 for an ounce of platinum, making it worth 

 considerably more than eight times as much 

 as gold. Many coin collectors are familiar 

 with the Russian platinum coins issued be- 



