550 TRANSACTIONS OF THE 



They put the ore into tte crucible, and at the end of the roasting found 

 nothing left but a blackened sand. The shining particles had escaped. If 

 it -was a metal, it was volatile and invisible at its escape. They then tried 

 to fix it by combining some other substance. In these experiments they 

 tried copper. The result was a bright yellow metal, harder and heavier 

 than copper, which they at first mistook for gold, but were finally content 

 to call "brass," Sixty pounds of copper treated with the strange ore 

 gave them 100 pounds of brass. They had discovered a new metal, and 

 set vigorously at work to separate it from impurities and alloys, and finally 

 succeeded in confining its volatility and producing metallic zinc, which 

 the first ships of the East India Company brought from China at about 

 twenty-four cents a pound. Still it was a brittle, intractable metal, fit 

 only to make brass. But the uses of brass increased rapidly, and the 

 desire to cheapen that useful metal led to the invention, in Europe, of the 

 retort process of obtaining zinc metal. This was followed (in 1806) by 

 the discovery of the vast deposits of zinc ores in Belgium and in Silesia. 



The products of these mines soon glutted the market of the world, and 

 brought down the price from twenty-four to four cents a pound. 



Ingenious men undertook to find out new uses for this cheap metal. 

 Their attempts were rewarded by three inventions, which are to be noticed 

 in the order of their occurrence. 



A man of Glasgow undertook to handle metallic zinc at every tempera- 

 ture. At 230 deg. of Fahrenheit he found it malleable and ductile, and 

 up to 300 deg it behaved in the same laudable manner ; and this capacity 

 for good conduct continued in the rolled metal until it was again heated 

 above 300 deg., when it again became intractable and crusty. 



Immediately " sheet zinc " began to take the place of sheet iron, sheet 

 tin and sheet lead ; and being insoluble in water, and but slightly subject 

 to oxydation, it rose rapidly in favor with the public, and new uses were 

 constantly arising. This was the first invention. 



Meanwhile an ingenious Frenchman conceived the idea of converting zinc 

 metal into an oxyd, and using it in oil as a paint, in place of the oxyd of 

 lead, which was known to be poisonous to the painters, and to the inmates 

 of recently painted houses. 



He first obtained a coarse paint of a dull color, but after thirty years of 

 experiments, in 1849, Leclaire produced "zinc-white," which imme- 

 diately commanded such notice and commendation, and public patronage as 

 the French nation and government bestow only on great public benefac- 

 tions. This invention opened a market for all the zinc product at a better 

 price. This was the second invention. 



During the same period zinc-ores had come into notice at various points 

 in our country, from Sterling Hill, in Sussex county, N. J., throughout 

 the Saucon valley, extending southwesterly through Pennsylvania, Virginia 

 and Tennessee, but especially at Sterling Hill, and near Bethlehem, in 

 Pennsylvania. 



