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bottle have been well shaken up with a little fresh c. carminate 
of lead, they must be boiled in a porcelain evaporating dish and 
filtered boiling hot through a double filter of fine filtering paper, 
and the filter washed once or twice more with boiling water, 
and the matter on the filter collected and boiled over again and 
filtered again and washed with boiling water, as the c. carminic 
acid is but sparingly soluble even in hot water, and adheres 
ppeumately to the sulphuret of lead. 
(9) The filtrates may then be mixed together, and the 
liquor rendered strongly acid by acetic acid, this will cause after 
some time, or immediately if the liquor be warmed, a precipitate 
of pure c. carminic acid, combined perhaps with a trace of gela- 
tinous matter, this collected and dried in the shade resembles 
closely precipitated carmine, which indeed consists almost 
entirely of c. carminic acid, with the addition of a little alumina. 
(10) If now to the liquor from which carmine has been 
extracted in the process of carmine making, a few drops of a 
solution of acetate of barytas be added to precipitate any sul- 
phuric acid that may be present derived from the alum, and 
about an ounce of common acetic acid to precipitate any c. car- 
minic acid that may still remain uncombined with the carmine, 
and the liquor be filtered, and the filtrate rendered neutral by 
ammonia, and acetate of lead in sufficient quantity be added, 
(about 150 grains for the 840 of cochineal is ample), a beautiful 
bluish purple or purplish blue precipitate of purpureo carminate 
or (for short) p. carminate of lead ensues, this must be collected 
on a filter and well washed. 
(11) If now this precipitate (which seems to be as rich and 
beautiful a pigment in its way as carmine itself) be treated as 
the c. carminate of lead was, with sulphuretted hydrogen only, 
the gas may with advantage be passed through it for an hour or 
more, some fresh p. carminate being kept apart to absorb any 
sulphuretted hydrogen in the bottle at the end of the operation, 
and the liquor be filtered, washed with a little water, and the 
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