40 
METALLIC COMPOUNDS. 
Stibiate of 
potash* 
^mmoniacal 
loperstibiate. 
'& ary tic stibi- 
*te. 
producing a determinate or neutral compound when the affini- 
nities on which it depends are so feeble. 
The powder obtained by edulcorating the product of nitre 
burned with antimony, and from which boiling water extracts 
the neutral stibias kalicus, appears to be a stibir. acid, which is 
decomposed by the action of the boiling water into a neutral 
stibias and a stibic acid, or rather into a superstibias, with a 
still greater excess of acid. 100 parts of this powder, well 
washed with cold water (but not trea ed with boiling water) 
leaves., after treatment with nitric acid, a quantity of stibic acid 
combined with water, which, in one experiment, produced 
8374, and in anothei experiment 84 GO. It follows, that 100 
p. of stibic acid had been combined With 11*33 p. of pure 
potash. This quantity is rather less than half what is contained 
in the neutral stibiate. It appears f hat the effect of the cold 
water has changed it a little by dissolving a small quantity of 
neutral stibiate, and that, in fact, there is found a certain portion 
of the latter mixed with the nitrate and with the combination 
of oxidum stibicum and potash, which are taken up by the cold 
water. 
This circumstance explains why, in the prescription for mak- 
ing the calx antimonii elata of the pharmacopeia, it is expressly 
forbidden to fuse the mass, because, in this case, the supersti- 
bias kalicus decomposes the nitrite of potash, by disengaging 
its acid, and becomes a neutral stibiate, which is almost totally 
dissolved during the washing. 
The stibias hydricus is dissolved by strong digestion in caustic 
ammonia, and its solution appears to contain a neutral stibias 
ammonicus. It cannot be evaporated because, in this case, 
part of the ammonia would fly off, and a white precipitate 
would be formed, which reddens turnsole paper, and affords 
ammonia and water when heated in a glass retort, the stibic 
acid remains in the form of a yellow powder. The precipitate 
is, therefore, a superstibias ammonicus. This is not decomposed 
by the action of air, even if exposed at the temperature of 
40 p or 50° (105 c to 120° Fah.)for the space of several months. 
Stibias laryticus is a white powder which is obtained by 
precipitating the muriate of barytes with stibiate of potash. 
It appears to be perfectly insoluble in water, because the pre- 
cipitate produced by the h?st drop of the precipitant is not re- 
dissolved 
