108 PREPARATION OF CARMINE. 
ART. XXXV. — PREPARATION OF CARMINE. 
The following processes for the preparation of carmine, 
are taken from the 8th volume of Dumas' Traite de Chi- 
mie, appliquee aux Arts, which is just published. 
Carmine, prepared, with white of egg. — The carmines 
known under this name are made in the following manner 1 
P, Cochineal, ifej. giv. 
Carbonate of soda, gr. cxv. 
Soft or river water, Cong. iv. 
Boil these together for twenty minutes in a vessel, the depth 
of which is double its diameter, and which is furnished 
with two handles and a lip to facilitate the pouring out of 
the liquid. This boiler should also be furnished with an outer 
rim, which serves to support it over the furnace, so that the 
bottom alone is exposed to the fire. It should be heated 
with a wood fire, as the combustion of coal is found to be 
injurious to the quality of the carmine. 
After boiling for twenty minutes, the boiler is to be re- 
moved from the fire, and 5vj. of alum, and 3j. of cream of 
tartar added. The mixture is to be stirred for a few mi- 
nutes ; the pan is then to be inclined so that the liquor may 
be easily decanted, and then left to itself. By degrees the 
refuse of the cochineal is deposited — the solution, which 
was of a violet colour, assumes a rose tint, then a bright 
red. The liquor is at this time slightly turbid, and evi- 
dently contains the carmine in suspension, but in such a 
fine state of division that it cannot be separated by filtration. 
After standing at rest for about a quarter of an hour, the 
liquor is decanted, and passed through a very fine silk 
sieve. It is received into another pan, left at rest for a few 
minutes, and then decanted again, when a slight brownish 
deposit is left. 
The white of two eggs, well beaten up, is then added, 
