[ 862 ] 
And the fame is neceflary to the reduction of the calx 
of iron, tin, copper, ©V. That there remains no 
fulphur in any antimonial calx, fo prepared, is mani- 
feft, in that no one of them will deflagrate with 
nitre, nor be reduced to a reguline flate, without 
adding fome phlogifton. That the reguline nature 
and contexture are deftroyed in thefe preparations, 
appears in that they are not at all adted upon by 
aqua regia, which fo perfectly and readily diflfolves 
any antimonial regulus : and hence alfo they are 
utterly devoid of an emetic quality. 
But in all thefe calcinations with nitre, three parts 
at leafl: of that fait muft be ufed to one of the crude 
antimony, or the internal fulphur will not be fuffi- 
ciently burnt off, and the reguline fpicula fo far de- 
ftroyed as to leave an inert calx : for if two parts 
only of falt-petre are employed, it proves ff ill emetic, 
as is feen in what Boerhaave calls antimonii emeti- 
cum mitius : fo alfo if the nitre be confiderably re- 
duced, in the preparation of the cerufs of antimony, 
that likewife will remain very draftic. If equal 
quantities of nitre and glafs of antimony are ex- 
pofed for fome time, in a clean crucible, to a brifk 
lire, a very beautiful calx, or diaphoretic antimony, 
comes out, but altogether inadtive : if two-thirds 
however, or half only, of nitre is ufed, the calx is 
nothing fo white (the fulphur not being quite burnt 
off); and thence it remains (till emetic, efpecially if 
only half falt-petre is projected with the antimony. 
Upon this foundation may be made feveral forts of 
antimonial powders, more or lefs adtive, as more or 
lefs nitre is ufed j which, prepared with care, and 
given with judgment, may prove of conliderable 
fervice 
