ON WHITE LEAD. 
67 
facturers performed upwards of two thousand experiments in 
the course of five years, and produced an article of such a 
quality that in 1826 they obtained a premium for it from the 
Franklin Institute. 
2. In 1818, J. Richards obtained a patent for a process on 
similar principles, excepting that he appears to have employed 
only lead, air and water, (Jour. Frank. Inst, vol. xxvi, pp. 
125, 175.) The white lead was deficient in color and body, 
as may be seen in the Technical Collection of the Franklin 
Institute. 
3. In the Lond. Jour, of Arts and Science, vol. v., 1835, 
may be found a patent of Torassa, Muston and Wood, in 
which granulated lead was shaken in a moistened state on 
trays and the comminuted gray mass exposed to the air until 
a white lead was formed. From the date of the patent, 1833, 
it is very possible that the first ideas of the process were de- 
rived From G. F. Hagner, while the latter was in England 
in 1817-18, (Jour. Frank. Inst., vol. i., 3d series, p. 159.) "It 
is said that upwards of ^100,000 have been expended at 
Chelsea, by a joint stock company, for executing this most 
operose and defective process. " (Ure's Diet., p. 1300.) 
4. Notwithstanding the ill success of these processes, we 
find another patent, (Jour. Frank. Inst., vol. xxvi., p. 119,) 
taken out by Homer Holland, in which the same mode of 
making the white oxide, &c, is claimed by the patentee, ex- 
cepting that to make the carbonate, he introduces a portion of 
carbonate of soda into the water. In an amended patent 
(1838) he claims the use of any alcaline salt or substitute, 
whose elements consist of oxygen, carbon and hydrogen in- 
stead of alcaline carbonates. 
5. The Jour. Frank. Inst., vol. xxvi., p. 123, presents 
another patent by Smith Gardner for making white lead by 
attrition, with this variation, that the operation is conducted in 
close vessels into which carbonic acid and air are driven 
during the attrition, thereby presenting them, says the 
patentee, "to the suboxide of lead in its nascent state." "By 
