J. M. Ordway on Soluble Basic Salts of Tin. 223 . 
h 
importance, and one which seems likely, in connection with 
drawn from color. The fact that the sesquioxyd dissolves in: 
ammonia, while the protoxyd does not, of itself Ba ee nothing, 
lor why might not stannic acid render protoxyd of tin soluble 
in ammonia, just as arsenic acid does the sesquioxyd of iron? 
But the hydrated protoxyd and peroxyd of tin and their ordi- 
nary salts, as well as the stannates, are colorless, while interme- 
diate substances may be formed that are colored. This becomes 
Color appears to arise then during the deoxydation of peroxyd 
or of basic persalts, or the oxydation of the protosalts. So 
Protoxyd may enter into combination retaining their respective 
Colors, we seem forced to admit the existence of one or more 
intermediate oxyds of tin. 
Roxbury, Mass, January 10th, 1857. 
Gmelin m : “If a normal stannous salt is to 
be converted into a normal stannic salt se the action of air or nitric acid, it must 
first be mixed with a quantity of acid equal to that which it already contains; in 
default of the requisite quantity of acid, a precipitate is formed during pola 
tion, isti either of the hydrated stannic oxyd or a basic salt.”— : 
