collier] LITERATURE OF TIN DEPOSITS. 55 
considering the difficulty which may arise in separating wolframite 
from cassiterite the following information will be of interest: 05 
Since the latter part of 1903 there has been a very large increase in 
the demand for tungsten, and it is probable that from October 1, 1903, 
to October 1, 1904, will see the marketing of about 1,000 tons of tung- 
sten minerals. Where the tungsten mineral is an associate of some 
other economic mineral that is being mined it should be a valuable 
by-product. Its value varies with the percentage of tungsten oxide 
and has been about $100 per ton for a 55 to 60 per cent ore. As an 
associate of tin ore it should be of value as a by-product, and could be 
separated from the tin mineral by an electro-magnetic separator. 
As the demand for tungsten is limited there could readily be an 
overproduction, with a corresponding reduction in price. 
BIBLIOGRAPHY. 
The following are a few of the more important papers relating to the 
tin deposits in various parts of the world which may be useful for 
comparative purposes in estimating the value of the tin deposits of 
Alaska: 
Beck (Richard). Lehre von den Erzlagerstfitten, Berlin, 1901. Second edition, 
1903. 
Contains descriptions of the occurrence and method of mining tin ore, both in allu- 
vial and in lode deposits, in various parts of the world, and discusses the origin 
of tin ore. 
Blake (W. P.) . Tin ore veins in the Black Hills, and columbite and tantalite in the 
Black Hills: Trans. Am. Inst. Min. Eng., vol. 13, 1885, pp. 691-697. 
Structure of the Etta vein; percentage of black tin in the ore; minerals associated 
with the ore; extent of the tin region. 
Claypole (E. W.). The tin islands of the Northwest: Am. Geol., vol. 9, 1892, pp. 
228-236. 
Describes the structural characteristics of the igneous and sedimentary rocks that 
form the Black Hills and the movements of elevation and subsidence that have 
occurred in the region. The cassiterite is confined to the granite veins, and is 
very finely and irregularly disseminated. 
David (T. W. E.). Geology of the Vegetable Creek tin-mining fields of New England 
district, New South Wales: Geol. Surv. New South Wales, 1887, pp. 4-169. 
Minerals associated with tin ore; methods of mining stream tin; tin occurs both in 
recent gravels and in old channels covered by basalt flows; lodes from which the 
Vegetable Creek tin has been derived; average thickness, extent, and richness of 
the alluvial deposits. 
Emmons (S. F. ). Geological distribution of the useful metals in the United States: 
Trans. Am. Inst. Min. Eng., vol. 22, 1893, pp. 71-72. 
Describes the geologic occurrence of tin in various parts of the United States. 
Fairbanks (H. W.). The tin deposits at Temescal, southern California: Am. Jour. 
Sci., 4th ser., vol. 4, pp. 39-42, 1897; Min. and Sci. Press, vol. 75, 1897, p. 362. 
Describes the geologic features of the region and the occurrence of the vein system 
and the tin deposits. 
a Communicated to the author by Mr. Joseph Hyde Pratt. 
