OXIDES AND NITRATES OF LEAD. 137 



moniacal quintihasic nitrate of had. When sub-nitrates of 

 lead are boiled in often renewed ammonia, a green powder 

 is formed (which shall be enquired into hereafter), together 

 with a white powder, which from its light specific gravity 

 remains uppermost, and is easily separated by a few decan- 

 tations. It is then perfectly washed with boiled water, and 

 dried in vacuo over sulphuric acid. This white powder, 

 heated slightly, loses its water and ammonia without change 

 of colour ; but, if heated to a high temperature, it gradually 

 turns red, sets free its nitric acid, and leaves a beautiful 

 massicot, requiring a great beat for its fusion, a character 

 which is borne by all the massicot hereafter mentioned. 



This new salt, although insoluble in water, is readily dis- 

 solved in acetic and nitric acids. The analysis of this salt 

 and the following ones, does not present great difficulties ; 

 but still, as they have been taken by other chemists for sub- 

 nitrates of lead, and their ammonia overlooked, I think it 

 right to state here, w'ithout entering into all the details of 

 analysis, that if a solution of nitrate of lead be mixed with 

 ammonia, the insoluble salts produced invariably contain 

 water and ammonia, which latter is easily detected. These 

 compounds undergo two distinct stages of decomposition ; — 

 the first is the production of water and ammonia, and the 

 second is characterised by setting free at a higher tempera- 

 ture, nitric acid. 



The hydrated arilhoniacal quintihasic nitrate of lead 

 which I have just examined, gave by analysis the follow- 

 ing results : — 



Per cent. 



20 836 of substance left 18-089 of oxide, or 86-815 



5001 „ gave 0-417 of nitric acid, or .... 8-338 

 26-361 „ „ 4-198 of double chloride, or 0-710 



of ammonia, or ... . 2693 

 5-757 „ „ 0278 of water and ammonia, or 



0-125 of water, or . . . 2.171 



100-017 

 T 



