392 KANSAS CITY REVIEW OF SCIENCE. 



of acetic acid will serve in manufacturing an indefinite amount of white lead. 

 Until quite recently all of the white lead used in the arts has been made by one 

 of these processes. 



A few years ago a gentleman from Philadelphia, Mr. E. O. Bartlett, came 

 to Joplin city professing to have patented a process by which great quantities of 

 white lead could be saved from the vapors that escape up the flues of the smelt- 

 ing furnaces. His scheme was so plausible that he prevailed upon the smelting 

 firm of Moffit & Sargent to give it a trial. It proved to be a great success. In a 

 short time Mr. Bartlett sold his interest in the establishment and his patent right 

 on all the territory west of the Mississippi for $150,000. New and more com- 

 modious buildings were subsequently erected, and at the present time lead smelt- 

 ing and white lead manufacturing are conducted on a grand scale. To give the 

 reader some idea of the work now done by this one firm I insert the following 

 figures given me by Mr. J. H. Black, the foreman : 



Average amount of ore {lead sulphide) smelted per day . . 90,000 lbs. 

 Average per cent, of metallic lead obtained from same .... 66^ % 

 Average amount of metallic lead from slag resmelted . . . 14,000 lbs. 



Average amount of white lead per day .- 16,000 " 



Average price per thousand for same '. . $50 



It will thus be seen that the average proceeds per day from the white lead 

 alone is $800, or about $250,000 per year. I also learned that the pig lead ob- 

 tained from the slag furnaces more than paid all expenses of the whole establish- 

 ment, so that the 16,000 pounds of white lead and the profits on the 90,000 

 pounds of ore smelted are clear gain. 



The smelting furnaces of Joplin city and Short Creek lead mines are all very 

 much the same. They closely resemble the old Scotch hearth excepting instead 

 of having fiues three miles long to catch the escaping vapors, as the Scotch hearth 

 is said to sometimes have, the flues are vertical and comparatively low. The 

 furnaces are about twenty-two inches square and nearly the same in depth. A 

 cold air blast, the force of which the workmen can regulate, is sent into each 

 furnace to increase the draught. The bottom part of the furnace is left filled 

 with lead from day to day. The smelting process is briefly as follows : Char- 

 coal and ore, mixed with a little slaked lime, are thrown into the furnace. A 

 heavy blast of air is turned on and roasting is continued for some time, during which 

 the workmen are continually stirring the whole mass, and shoveling out the slag 

 that is formed from the lime and the silica that is mixed with the ore. During 

 the roasting the sulphur of the ore is oxydized into sulphurous oxide, which passes 

 up the chimney. The lead is oxydized into litharge, or lead oxide. After the 

 stirring has been continued for a few minutes the blast is almost entirely turned 

 off, fresh charcoal is added, and the whole is heaped up at the back side of the 

 furnace where it is left for a few minutes. The lead oxide formed is thus brought 

 in contact with carbon which deprives it of its oxygen, leaving metallic lead 



