TIN. 403 



tin formed in this way weighed 9*25 grains ; 

 hence it is evidently a compound of 



Tin . 7-25 



Oxygen . 2 



9-25 



But 2 denotes 2 atoms of oxygen ; consequent- 

 ly, 7*^5 must be the weight of an atom of tin. 

 Peroxide of tin obviously weighs 9 '25, and is a 

 compound of 1 atom of tin and 2 atoms of oxy- 

 gen. 



2. The experiments of Berzelius* leave no Atom . <> f 

 doubt that the protoxide of tin contains just half 

 the oxygen in the peroxide. It is, therefore, a 

 compound of 1 atom tin and 1 atom oxygen, 

 and its atomic weight is 8 '25. 



3. Tin combines with two proportions of chlo- Chlorides 

 rine, as well as of oxygen, and forms two chlo- 

 rides. The protochloride is most easily formed 

 pure, by amalgamating together tin and mer- 

 cury, mixing the amalgam with a sufficient quan- 

 tity of calomel ; and exposing it in a glass tube 

 to a heat at first low, but gradually raised high 

 enough to expel all the mercury and the calo- 

 mel. J'%5 grains of tin treated in this way, left 

 11'75 grains of protochloride. Hence this chlo- 

 ride is obviously composed of 



Nicholson's Journal, XXXV. 122. 

 Cc2 



