OXIDES AND NITRATES OF LEAD. 145 



2. I have succeeded in combining in one proportion the 

 oxide of lead with ammonia, and therefore have pro- 

 duced a plumbate of oxide of ammonium, or plumbate of 

 ammonia, with one equivalent of water. I hope that this 

 new compound will give us the clue to combinations of 

 ammonia with a greater number of oxides than hitherto. 



3. I think that most of the directions published for pre- 

 paring the hydrate of oxide of lead are imperfect, and that 

 the one I give will prove satisfactory. 



4. I have succeeded in preparing a new series of salts, 

 in which one equivalent of oxide of lead is gradually 

 replaced by one of ammonia; they therefore present a simi- 

 litude to the action of chlorine in some organic bodies: 

 that is to say, the ammonia replaces the oxide of lead 

 without changing the harmony which exists in the mole- 

 cular arrangement of the component parts of the salts. 



5. I have also obtained hydrated tri-nitrate and sexbasic 

 nitrates of lead, in which one or two equivalents of the water 

 of crystallization are substituted or replaced by one or two 

 equivalents of ammonia. 



6. The above salts show the influence that the degrees 

 of concentration of liquors, and the mode of operating, 

 have on the molecular arrangements of insoluble salts; and 

 I am led to remark, that it is the first instance we have of 

 the influence of different degrees of concentration of solu- 

 tions on the products which result from their admixture. 



7. I have also obtained a new class of compounds, which 

 are interesting, owing to the tenacity with which they re- 

 tain a small amount of nitric acid. 



8. Lastly : I have prepared different sub-nitrates of lead 

 by pouring caustic potash into the nitrate of that metal. 



