66 
ON WHITE LEAD. 
ART. IX.— ON WHITE LEAD By James C. Booth. 
The large quantities of white lead employed as a pigment 
by our painters, the number of patents which have been is- 
sued abroad, proving its extensive employment, the large 
amount of capital invested in its manufacture, bespeak a mate- 
rial of no ordinary importance, and lead us to inquire whether 
the processes by which it is produced may not be improved 
relatively to economy and convenience. Undoubtedly one 
method by which this end may be attained is by a thorough 
knowledge of the chemical principles which are involved in 
its production, ere we can take a higher step in the applica- 
tion of chemistry to its improvement; and it is to this point 
the following remarks will be directed, by investigating the 
theory of the processes which are now pursued. 
There are three principal modifications of the processes for 
producing white lead, which will include all the patents that 
have been granted, subject of course to such variations as se- 
cure the privileges of numerous patentees. They are those in 
which the formation of white lead is in whole, or in part, in- 
duced by atmospheric agency, those operating by single, and 
lastly those by double elective affinity. 
I. Triturating Processes. — 1. The earliest account which 
I have been enabled to procure of the manufacture of white 
lead by the action of atmospheric agents alone, or in chief 
part, will be found in this Journal, vol. i, 3d series, p. 158, 
from which it appears that G. F. Hagner obtained a patent for 
such a process in 1817. Finely granulated metallic lead was 
made to revolve in cylinders with water and a portion of vine- 
gar, the air having access; by which means it was converted 
into a white substance, a mixture of carbonate and hydrate, as 
we shall find below. When used as a pigment, this white 
lead was very liable to become yellow, in consequence of 
which the process was so varied as to fall more evidently un- 
der those dependant on single elective affinity. The manu- 
