THE WORLDS ANNUAL METAL CROP 281 



be seriously delayed. The metal is almost as resistant as gold to the 

 action of air and water, and to the attacks of those acids which exist 

 in foods of all kinds, and which in a few weeks would destroy iron, 

 and convert copper, lead or zinc into poisons, and kindly nature has 

 segregated it in the crust of the earth in places where it may be col- 

 lected at moderate cost, and utilized in activities that have become 

 quite of the nature of indispensables to the further progress of hu- 

 manity. 



Zinc 



This metal, which a thousand years ago was a puzzle to the metal- 

 lurgists, and a nuisance to the lead miner, has become, during the last 

 quarter of a century, one of the most useful and necessary products of 

 the mine. The demand has increased so enormously that producers 

 have at times had the greatest difficulty in meeting it. We have no 

 reliable statistics of the world's output previous to 1883, when it 

 amounted to 310,000 tons. Its principal use up to that date was for 

 the production of brass, an indispensable alloy in the manufacture 

 of bearings and fittings for all kinds of machinery. Previous to the 

 present mechanical age its only use was in ornamentation. Now 

 many other employments have been found for the metal. In the 

 condition of an oxide it is consumed very extensively by the paint 

 manufacturers. In the form of an electrically deposited coating on 

 sheet iron it is in great demand by the building trade for cornice 

 work, etc., under the name of galvanized iron, and is exported in 

 enormous quantities to all new parts of the world for use as roofing 

 and siding in those temporary structures reared for protection against 

 the weather in lands where lumber is not available at reasonable cost. 

 With the development of the electrical industries it has become a 

 necessity in many forms of batteries, and during the last dozen years 

 or so hundreds of tons have been consumed annually in the recovery 

 of gold from certain of its ores by means of what is known as the 

 cj^anide process. These new uses, as well as the steady increase in 

 the demand for brass in the ever-growing machinery trade, have 

 caused its production to grow with such rapidity that in 1906 the 

 crop amounted to 774,525 tons, a gain of 250 per cent, in twenty-four 

 years. Zinc is not reckoned as one of the heavy metals, nor yet is it 

 a light one, its specific gravity being a little less than that of iron. 

 Yet if the product of last year was melted and cast into a pyramid 

 with a base of an acre, the apex would stand at an altitude of about 

 250 feet. This is a fairly good record for a metal that in 1850 was 

 practically unused except in the form of brass. By itself, it is a 

 beautiful substance, almost as soft as lead, very malleable, and with a 

 rich blue-white luster that is the delight of the artist. 



History seems to indicate very clearly that nations who have pos- 



