46 



REPORT — 1839. 



the calculations in the sequel, as the experimental increase on 100' of 

 lead in becoming the sulphate : 



Greatest 46-431 

 Mean 46-401 

 Least 46-374 



A known weight of dried nitrate of lead was likewise, by Turner, 

 dissolved and heated with sulphuric acid, so as to form sulphate. Cor- 

 rections on account of the buoyancy of the air and of acid-impurities 

 having been made, 100- of sulphate of lead were produced from — 

 Nitrate. 



1, 109-312 



2, 109-310 



3, 109-300 



Mean 109-307 



These results come very near each other. But according as 100- of 

 lead, in becoming the sulphate, increases 46-431, 46*401, or 46*374, 

 the proportion of lead in its nitrate will vary, on account of the uncer- 

 tainty of the composition of the resulting sulphate, altogether inde- 

 pendent of the small variation in the proportion of nitrate that pro- 

 duces a given weight of sulphate. 



Greatest. 

 Sulphate 146*431 



from 

 Nitrate 160-067 

 160-065 

 160-050 



Sulphate 100- 

 from 



Nitrate 109-312 

 109*310 

 109*300 



(Mean) 109*3075 



160*060 



Mean. 

 146*401 



160*035 

 160*032 

 160*017 



160*027 



Least. 

 146*374 



160*005 

 160-002 

 159*987 



159*997 



146*431, 146*401, 146*374, being the quantities of the sulphate of 

 lead that were formed from 100* of lead, it follows that the quantities 



of nitrate 160-067 159*987 should likewise contain 100- of lead. 



Bringing then together the results of the experiments on the sulphate 

 and on the nitrate, it appears that the following are the increments of 

 weight that 100* of lead acquires in becoming, 



Sulphate. Nitrate. 



Greatest 46-431 .... 60-067 

 Mean 46-401 .... 60-027 

 Least 46-374 .... 59-997 

 The increase of weight that lead acquires in becoming sulphate, is 

 generally admitted to be due to the acquisition of one atom of sulphur 

 and four atoms of oxygen. In the case of the nitrate, however, while 

 the generality of chemists regard the oxygen acquired to be six atoms, 

 the azote is, by some, considered as one atom ; by others, as two. 

 With Dalton and Berzelius, I regard the azote as constituting two 

 atoms. 



