1815.] connected with the Atomic Theory. 185 



volumes of the Annals of Philosophy, pointed out some difficulties 

 which present themselves when we apply the atomic theory to the 

 salts, and having in a recent paper refused to admit Mr. Dalton's 

 attempts to remove these difficulties as valid — perhaps the reader 

 will not be displeased if 1 state here, in as few words as possible, 

 how I liave been in the habit of viewing these difficulties when they 

 Jiappened to present themselves during my examination of the 

 different genera of salts. When a difficulty occurs in any branch 

 of chemical investigation, the greater number of persons there are 

 who attempt to explain it, so much the sooner, in all probability, 

 vill it be removed. Even should my explanations not prove per- 

 fectly satisfactory, they may serve to convey a lucky thought to 

 some other person, who may be more fortunate in his endeavours. 



1 . It appears from the tables of the sulphates, carbonates, and 

 nitrates, published in the second and third volumes of the Annals 

 oj" Philosophy, that the yellow oxide of lead combines always with 

 two integi'ant particles of acid when it constitutes neutral sulphate, 

 carbonate, and nitrate of lead. The same law holds in the phos- 

 phate, borate, oxalate, and all the other neutral salts of lead. 



Nitrate of lead is composed of 2 7i + \ I 41 -580 



Sulphate of potash 1 s + 1 p 11-000 



52-580 



Now if we mix 41*58 grains of nitrate of lead with II grains of 

 sulphate of potash a double decomposition will take place, and two 

 neutral salts will be produced, namely, nitrate of potash and sul- 

 phate of lead, composed as follows : — 



Nitrate of potash ... . In + Ip 12-803 



Sulphate of lead 2s +1/ 37-974 



50-777 



Now it is obvious to the eye that if the two salts be composed as 

 we have supposed, such a double decomposition is impossible. 

 The first two salts contain two integrant particles of nitric acid ; 

 the last two, only one integrant particle ; while, on the contrary, 

 there is only one integrant particle of sulphuric acid in the first two 

 salts, but two in the last two. 'J'he weight of the first two salts is 

 5258 grains ; that of the last two, 50-777 grains. Thus about two 

 grains of weight are lost by the decomposition ; while a panicle of 

 nitric acid niuit bo transmuted into a particle of sulphuric acid. 

 Tiie same absurdities and contradictions will be found to take place 

 whenever we attempt to reduce any double decomposition, by means 

 of a salt of lead, to calculation. 



It is very obvious, from the appearance of tliese contradictions 

 and absurdities, that there must exist some error in our tables; 

 that the salts of lead cannot be constituted as we have supposed 

 them. Now a very slight aUeration will remove all the anoujalifs. 



