452 Notices of the Labours of Continental Chemists. 



is dissolved in water. This salt consists of C 24 H 44 O 22 + 3 Ca O. 

 The compound containing two atoms of lime, 14 per cent., is 

 much more difficult to prepare ; an excess of sugar must be used 

 (sugar thirteen parts, unslaked lime two parts), the salt must 

 be precipitated from its solution by alcohol. Soubeiran could 

 not obtain any other compound of lead but that with four 

 atoms of base. 



The compounds with potassa and soda have been examined 

 by Brendecke, but are difficult to procure in a pure state, and 

 are moreover deliquescent. Soubeiran did not make any ex- 

 periments on them. From his researches he considers the 

 constitution of an atom of sugar to be C 24 H 36 ' O 18 = S, and 

 the salts may be arranged as follows : — 



Crystallized sugar == S-f-4aq. 



P °comp } = S + R0 Lead com P' = S + 4PbO. 



... P robably=S+ {f^O) Lime ... = S+|3 (C.O+EPO) 



Soda =S+ Na'o Lime ... = S 4 {| ^ a ° + H2 °> 



...probably^ S+ { f^' W0) ^'^ % =S+ {|^° +IP0) 

 Chloride of sodium l_o, fNaCl 2 

 compound J ~~ \ 3 aq. 



(Journ. de Pharm. et deChim. Juin 1842.) 



Plumbo-Sulphate of Ammonia. 



Sulphate of lead is considerably soluble in sulphate of am- 

 monia, particularly when boiled. A double salt crystallizes 

 out on cooling ; the best method of obtaining it is to precipi- 

 tate a tolerably concentrated solution of acetate of lead with 

 excess of dilute sulphuric acid ; it is then neutralized with am- 

 monia, and the whole boiled, by which the sulphate is dis- 

 solved. If this does not take place there is a want of sul- 

 phate of ammonia ; if the solution does not deposit crystals 

 on cooling, sulphuric acid must be added until turbidness 

 commences. It appears as if the salt were easier formed when 

 acetate of ammonia is present. The double salt forms small, 

 but bright well-defined crystals. It is decomposed by water, 

 and also by heat, when sulphate of lead and sulphite of am- 

 monia are formed : the latter salt sublimes. It does not con- 

 tain water of crystallization. According to the analysis of 

 Professor Litton, its formula is Pb O, S 3 + N 2 H 8 O, S O 3 . 

 — (Ann.der Chem. und Ph., vol. xliii. p. 126.) 



