Intelligence and Miscellaneous Articles. 599 



with Berzelius and Chevreul as to the oxide of lead ; but he is of 

 opinion that these salts, of which he finds there are three, contain 

 nitrous acid, formed, according to the experiments of Dulong, of 

 two volumes of azote and 4 volumes of oxygeq, and is prepared by 

 the decomposition of nitrate of lead. 



The salt discovered by Proust is prepared by dissolving an equiva- 

 lent of neutral nitrate of lead, 1 66, in about fifteen times its weight 

 of water, and putting into it an equivalent of lead, 104, in very thin 

 plates, when heated to about 140° to 155° F. If more lead be used 

 the orange salt is formed, if less, dinitrate of lead is obtained 

 with the yellow nitrite ; if the heat be not greater than above stated, 

 no nitric oxide gas is formed. 



The results of the analyses of this salt are given by M. Peligot as 

 under : — 



Az 177-04 5-0 



O 4 400-00 11-7 



2PbO 2789-00 80-1 



HO 112-50 3-2 



3478-54 100- 



Converting these into English equivalents, this salt is composed 

 of nearly — 



One equivalent of nitrous acid 46 .... 16'5 



Two . . . protoxide of lead 224 80-2 



One ... water ,, 9 3-3 



279 100- 



The next salt examined by M. Peligot was the orange-red com- 

 pound. It is prepared by boiling one equivalent of nitrate of lead 

 with one and a half of lead. The composition of this salt is stated 

 to be — 



Az 2 3540 31 



O 8 800-0 7-3 



7PbO 9761-5 ...:.. 86-7 



3HO 337-5 _2^9 



11253- 100- 



English equivalents will give 



Two equivalents of nitrous acid 92 .... 10 - 2 



Seven . . . protoxide of lead . . 784 .... 86*9 



Three . . . water _27_ 29 



903 100- 



This salt may also be procured by boiling a solution of the yellow 

 nitrite with protoxide of lead. 



The last salt analysed by M. Peligot is very sparingly soluble in 

 water, 10,000 parts at common temperatures dissolving only eight 

 parts, which are taken up by 290 parts of boiling water. In order 

 to form this salt, the lead must be boiled in very dilute solutions of 

 the nitrate. When the water holding it in solution is quickly cool- 

 ed, this salt precipitates in the state of a white powder, whereas, by 

 slowly cooling, silky crystals of a light rose-red are obtained, re- 

 sembling carbazotate of ammonia. 



