424 ‘Progress of Foreign Science. 
It is very soluble in water and in alcohol; water at the tempe- 
rature of 10° C. (50° F.) dissolves one third of its weight. 
The watery solution has a strongly acid taste, it does not preci- 
pitate lime or barytes water, nor the greater part of me- 
tallic solutions, with the exception of acetate of lead, and pro- 
tonitrate of mercury. With the oxides it forms salts possessing 
properties different from the citrates. 
The pyrocitrate of potash crystallizes in small needles, which 
are white, and unalterable in the air. It dissolves in about 4 
parts of water. Its solution gives no precipitate with the nitrate 
of silver, or of barytes; whilst that of the citrate of barytes 
forms precipitates with these salts. 
The pyrocitrate of lime directly formed, exhibits a white 
crystalline mass, composed of needles, opposed to each other, 
in a ramification form. This salt has a sharp taste. It dis- 
solves in 25 parts of water at 50° Fahr. It contains 30 per 
cent. of water of crystallization; and is composed, in its dry 
state, of 
J yr i Re SM ae Sd OG 
The solution of the pyrocitric acid saturated with barytes 
water, lets fall, at the end of some hours, a very white crystal- 
line powder, which is pyrocitrate of barytes. This salt is solu- 
ble in 150 parts of cold water, and in 50 of boiling water. Two 
grammes of this salt decomposed by sulphuric acid, furnished 
1.7 of sulphate of barytes, which gives for its composition, 
Pyrocitric acid 2. 6s ee 43.9 
Barytes 55). es Pe ese Aas ss 56.1 
The pyrocitrate of lead is easily obtained by pouring pyro- 
citrate of potash into a solution of acetate of lead. The pyro- 
citrate of lead presents itself under the form of a white gelatinous 
semitransparent mass, which becomes dry in the air, shrinking 
like gelatinous alumina, to which, in its physical characters, it 
has much analogy. It contains 8 per cent. of water, and is 
formed of 
Pyrbeltvic: acid: fics ai iei2 Laiiecers 33.4 
Protoxide of lead ........ 66.6 
Knowing the composition of pyrocitrate of lead, it was em- 
ployed, by ignition with oxide of copper, to determine that. of 
the acid itself, which is stated as being 
Cameos’ |. 5 Genie al stip ie ee hd 47.5 
QacivFem sis. OIL Anse Fell) ohn 43.5 
Hydrogeni(c) ance) wer ehh 9.0 
