Gas lights. 1gi 
a hens egg and placed in piles of thirty tons upon which 
water is thrown ; a spontaneous Combustion takes place— 
sulphuric acid is readily formed, which takes hold of the 
iron—the piles continue hot until the mass is pulverized 
when it cools and is lixiviated. When the pieces of ore 
are large or the pile small, the sulphate of iron does not 
readily form. Boston is the principal market for the cop- 
peras. 
INTELLIGENCE AND MISCELLANIES. 
——_——_——— 
I. Foreren. 
Extracted and translated by Prof. Griscom. 
1. Crystallization of sub-carbonate of potash.—Fabronta 
chemist of Tuscany, states in the Annales de Chimie 
on cooling, all the foreign salts are precipitated. The hi- 
quor is then decanted and evaporated to the 55°. It is, 
at this point, slightly green, and has a penetrating alcaline 
odour. It is poured into a deep vessel, and crystals are 
soon formed in long rhomboidal plates, parallel and verti- 
cal, resting on the bottom of the vessel, while the upper 
ends are attached to a saline crust which covers the sur- 
face. Fresh crops may be successively formed by concen- 
trating the mother water to 55°, until the whole of the 
sub-carbonate is crystallized. By this means, he conceives 
a sub-carbonate of potash, quite pure, and of uniform pro- 
Perties may be obtained. ‘ 
