594 LEAD. 



facts, also formed a quadribasic nitrite of lead, containing 

 NO 3 , 4PbO and HO. 



Acetate of lead, PbO, (C 4 H 3 O 3 )+3HO. This salt is met 

 with well crystallized, and in a state of great purity in commerce. 

 It is generally prepared by dissolving litharge in the acetic acid 

 procured by the distillation of wood. It crystallizes in flat- 

 tened four sided prisms, has a taste which is first sweet and 

 then astringent, is very soluble in water, 1 00 parts of water dis- 

 solving 59 of the salt at 60, and soluble in 8 parts of alcohol. 

 It effloresces in air, and is apt to be decomposed in part Iby the 

 carbonic acid of the air, and thus to become partially insoluble. 

 It loses the whole of its water when dried at the usual tempera- 

 ture in vacuo. M. Payen crystallized the anhydrous acetate, 

 from solution in absolute alcohol. 



Tnbasic subacetate of lead, PbO, (C 4 H 3 O 3 )+2Pb O, is 

 formed by digesting oxide of lead in a solution of the neutral 

 salt, till it is strongly alkaline. This salt does not crystallize 

 when so prepared, but may be dried, and then contains no 

 water. It is very soluble, out must be dissolved in distilled 

 water, as the carbonic, hydrochloric and other acids, in well 

 water, precipitate its oxide of lead. M. Payen has observed 

 that the tribasic subacetate crystallizes readily, in fine prismatic 

 needles, when formed by adding ammonia to a moderately 

 strong solution of the neutral acetate. The crystals contain 

 1 eq. of water, which they lose at 212. The acetate of ammo- 

 nia formed at the same time, appears to give stability to the 

 subacetate of lead in solution, and prevents ah excess of a 

 whole equivalent of ammonia from throwing down any oxide 

 of lead from the solution. This ammoniacal solution of the 

 subacetate of lead, prepared without an excess of ammonia, is a 

 convenient form in which to apply that salt as a reagent.* 



Sesquibasic acetate of lead, 3 PbO, 2(C 4 H 3 O 3 )+HO.- 

 Was obtained by Payen by adding 3 eq. of the neutral acetate, 

 to a concentrated and boiling solution of 1 eq. of the tribasic 

 nitrate. It is also produced when the neutral and anhydrous 

 acetate of lead is heated in a retort or porcelain capsule, till the 

 whole, after being liquid, becomes a white and porous mass. 

 The sesquibasic acetate is then formed by the decomposition of 

 3 atoms of neutral acetate of lead, from which there separate 



* Me'moire sur les Acetates et le Protoxide de Plorab, par M. Payen, An. 

 de Chim. et de Phys. t. 66, p. 37. 



