﻿On the Zinc Mines of Franklin , N. J. 263 



I. 50 grs. of the powder were dissolved in dilated nitric acid, 

 excepting some light scales, without the application of heat. 

 The undissolved parts, separated by a filter, were dried ; their 

 weight was 0220. When decomposed by a mixture of nitric 

 and hydrochloric acids, a clear yellow solution was obtained, in 

 which an excess of pure ammonia gave a red brown oxide, free 

 from manganese, and having the characters of peroxide of iron. 

 The ammoniacal solution contained neither oxide of zinc or man- 

 ganese. 



II. By slowly evaporating the fluids produced by washing the 

 insoluble part with the nitric solution, an excess of nitric acid 

 was removed. The saline mass was not wholly soluble in water, 

 peroxide of manganese remaining. The fluid, rendered acid with 

 nitric acid, was boiled on the peroxide of manganese, and, while 

 warm, a slight excess of chlorite of potash was added, to precipi- 

 tate all the oxides. When cold, the fluid was diluted, and treated 

 with nitric acid in a dilute state, until after the escape of chlorine 

 an acid fluid was obtained. A brown bulky oxide remained un- 

 dissolved, which was readily separated by a filter, and washed 

 in boiling water. Dried and heated to a bright redness for some 

 time, there remained 3*212 grs. 



The brown oxide, in hydrochloric acid, gave chlorine and dis- 

 solved, affording a yellow solution ; rendered neutral by ammonia, 

 and mixed with a solution of succinate of ammonia, a precipitate 

 was obtained, which, by calcination with nitric acid, gave 0*180 

 of peroxide of iron. The manganese solution was oxidized by 

 chlorite of potash, and warmed in a solution of ammonia, no ox- 

 ide of zinc could be detected. 



III. The solution and washings from the brown oxides of II, 

 were evaporated, and alkaline chlorite of potash added, till a small 

 precipitate was produced ; by boiling the fluid on the precipitate, 

 the white color of the latter was unaltered. Carbonate of potash 

 in excess was added to the liquor, and the whole evaporated to a 

 paste. Boiling pure water left a snow white carbonate undis- 

 solved, which was washed on a filter. The fluid from the car- 

 bonate, with the washings, were mixed with hydrosulphate of 

 ammonia; a trifling precipitate of a white color was obtained, 

 which was calcined, dissolved in nitric acid, the solution mixed 



solution of carbonate of potash, and the minute 

 quantity of carbonate added to that on the filter. The carbo- 



