640 



RECORD OF MEETINGS OF THE 



Nickel needs to be present in amounts of several per cent., 

 say two to five, and occurs either alone or with copper. Cobalt 

 is always with it in small amounts. Platinum occurs in exceed- 

 ingly small percentages. It is almost all obtained from gravels 

 in Russia, and the gravels yielded in 1899 according to C. W- 

 Purington about forty cents to the yard, platinum being quoted 

 in that year at $15 to $18 per ounce. There was, therefore, 

 in the gravels about one fortieth ounce in the yard, or one 

 sixtieth in a ton, or about 5.5 hundred thousandths of a per cent. 

 Platinum in some rocks has been found in amounts of one 

 twentieth to one half ounce, or from 16 hundred. thousandths to 

 16 ten thousandths of one per cent., but they are rare and 

 peculiar types. 



In order to be salable manganese ores of themselves must yield 

 about 50 per cent., but if iron is also present they may be as 

 low as 40. Chromium has but one ore, and it must contain 

 about 40 per cent. Of antimony, arsenic, and cobalt it is 

 hardly possible to speak, since, except perhaps in the case of 

 the first, they are unimportant by-products in the metallurgy 

 of other ores. 



In summary it may be stated that in the ores the metals 

 must be present in the following amounts : 



Percentage in Ores. 



Ounces to Ton. 





Percentage in Earth's C 



Iron, 



Copper, 



Lead, 



35-65 

 2—10 



7-5° 





4.71 

 .0000X 

 . 0000X 



Zinc, 



25-60 





.0000X 



Silver, 



1/12-1/150 



2-25 



.000000X 



Gold, 



1/300-1/6,000 



1/20-1 



. 0000000Z 



Tin, 



J -3 





. 000X— . 0000X 



Aluminum, 



3° 





8.13 



Nickel, 



2 -5 





. 01 



Manganese, 

 Chromium, 



5° 

 40 





.07 



.01 



We now have before us some fundamental conceptions from 

 which as a point of departure we may set out upon the real 

 discussion of the subject. We understand the gross composition 

 of the outer earth ; we have some idea of the quantitative distri- 

 bution of the metals in the rocks, especially in the richer in- 

 stances; finally we have seen the extent to which they must 



