OXIDES AND NITBATES OF LEAD. 



135 



an indefinite period, when excluded from the action of the 

 atmosphere. Heated slowly, it gives off water and ammonia ; 

 but it is necessary that the heat should be carried to red- 

 ness ere the whole of the water and ammonia is dissipated. 

 On the application of heat it first assumes a dark red 

 colour, then decrepitates, and leaves when cold a beauti- 

 ful crystalline yellow massicot. The plumbate of am- 

 monia is easily decomposed by nitric, hydrochloric, sul- 

 phuric and acetic acids. Thrown into melted soda, it gives 

 the red oxide. The numbers obtained have led me to 

 assign the following composition to this compound : 



Per cent 



9-754ofsubstence left 9044 of oxide of lead, or . . . 92200 



8-550 „ gave 2-361 of double chloride,* or 0-663 



of ammonia, or ... , 6-604 

 11-668 „ „ 0-849 ofwater and ammonia, or 0'286 



100000 



ACTION OF POTASH ON NITRATE OF LEAXt. 

 By pouring caustic potash into a more or less diluted a)lu« 

 tion of nitrate of lead, I obtained three salts, two of which 

 were already known, namely, the hydrated, tribasic, and 

 sexbasic nitrates of lead. It is mentioned by authors, that 

 they are prepared by the action .of ammonia on the nitrate of 

 lead, in which case I always obtained nitrates containing 

 ammonia. I shall only state, that I prepared the tHhasic 

 nitrate of lead, by pouring a solution of potash, having a 

 specific gravity 1*076 at 50*^ Fahrenheit, into a solution of 

 nitrate of lead of a specific gravity 1*375 at 59° Fahrenheit; 



* Under the term double chloride, is meant the double chloride of 

 platinum and ammonium. 



