186 Olseruations on some Points [Maucw, 



and render the composition of the salts of lead quite conformable 

 to experiment. Reduce the weight of an integrant particle of 

 yellow oxide of lead to one-half the weight which 1 have given it in 

 jny original table, published in the second volume of the Armals of 

 Philosophy. Let the weight be 13-987 instead of 27 "974. In that 

 case all the salts of lead will be composed of one integrant particle 

 of acid and one integrant particle of oxide of lead ; we have 



Nitrate of lead composed of \ n + \ I 20790 



Sulphate of potash \ s + \ p 1 1-000 



31-790 

 Forming, 



Nitrate of potash \ n + \ p 12*803 



(Sulphate of Itad 15 + 1/ 18-987 



31-790 



Here the double decomposition is obviously possible. The weight 

 of the first two salts is just the same as that of the last two, and the 

 number of integrant particles is the same in both. 



It seems to rne to be absolutely necessary to remove this anomaly 

 from the salts of lead ; nor do 1 see any other method of doing so 

 e.'icept the one I have just now proposed ; but if we reduce the 

 ^veight of an integrant particle of yellow oxide of lead to one-half, 

 ft is obvious that it must no longer be considered as a compound of 

 1 atom lead + 2 atoms oxygen, but of 1 atom lead + 1 atom 

 oxygen. It will be a protoxide instead of a deutoxide. If so, 

 provided it be true that the brown oxide contains just twice as much 

 oxj'gen as the yellow oxide, numbers adopted on the authority of 

 Berzclius, the brown oxide must be a deutoxide of lead composed 

 of 1 atom lead + 2 atoms oxygen. The red oxide, which is inter- 

 mediate, must be considered as a compound of one integrant par- 

 ticle of yellow oxide and one Integrant particle of brown oxide. 

 This notion was fii-st suggested by Proust, and appears to have been 

 adopted by Mr. Dalton. I own that in consequence of the anomaly 

 which I have just pointed out I have been for some time inclined to 

 the same opinion ; but a desire previously to examine the properties 

 of the red oxide of lead under this point of view has hitherto pre- 

 vented me from making any alteration in the weight of an atom of 

 lead. Berzelius refuses to adopt this opinion. There is, no doubt, 

 another method of getting rid of the anomaly which has been 

 pointed out above without having recourse to it ; namely, to double 

 the \Veight of an atom of all the other metals ; but that method 

 would be attended with much greater inconveniences, and could 

 not therefore be adopted with propriety. I do not see any alterna- 

 tive, therefore, in the present state of our knowledge, but that of 

 adopting the opinion of Proust respecting the nature of red leady 

 and considering yellow oxide of lead as a protoxide. 



If any person has taken the trouble to study the tables of the 



1 



