go E. DIVERS AND T. HAGA. 



ing on heating and re-forming on cooling (ß). The basic acetate 

 being in excess, instant precij^itation takes place. Tlie K.-, salt in 

 excess with basic lead acetate behaves as with the normal acetfite [cf. 

 Fremy). With the basic acetate in excess it reacts in the same way as the 

 normal potassium salt. The normal ammonium salt with basic lead 

 acetate behaves essentially as the sodium salt, but the solvent action 

 of ammonium salts prevents complete precipitation. Except when a 

 basic acetate in excess is used, the uK^ther-liquors of the lead precipi- 

 tates are ricli in the two-thirds normal salt of the alkali metal used, a 

 ficf pointed out by Fremy, but emphaticilly denied by Claus, 



Description of tlie .•■ictlts. — Like other oximidosidphonates the lead 

 salts combine readily and in varying proportions with other salts. 

 Accordingly, several double salts of lead and S(xlitim, of lead and 

 potassium, And even <^f lead and hydrogen can be prepared. These 

 are ])artlv decomposed b\' water, ])ut washing even with luit water 

 never removes all alkali salt. In nearly all the salts the lead is 

 present half as livdroxide or oxide. An exception is the unstable 

 two-thirds normal load salt. With admissible and only slight 

 (pialifications, all the salts we have analysed may l)e expressed as 

 derivatives of one. two, three, or fiiir molecules of the acid. 



(1) Tirn-lJiirils Hornuil lead n.rimidosHjplioNalc, PldTXS^O;. This 

 si'.lt can be obtained from tlie normal liydroxy-lead salt (2) which is 

 insoluble in water, by stirring it with water containing almost enough 

 sulphuric acid to deprive it of two-thirds of its lead. The mother-liquor, 

 which is slightly acid, when mtiderately evap<H-atc(l in the desiccator 

 gives a crust of minute crystals. These aj^pear nndci' the microscope 

 as trans])arent prisms somewhat hollowed at tlieii' middle to a dumb- 

 bell-shape. Tlie salt is oidv sparingly so]ul)l('. and is very unstalile. 

 We have not analvsed it. 



(2) NoniidJ ]iiiilro.ri/-h'iiil oxiinidosuljijioiiatr, (1 lOPb)3NS.O;, 



