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MANUFACTURE OP PROTOCHLORIDE OP TIN. 
ART. X.— ON THE MANUFACTURE OF THE PROTO- 
CHLORIDE OF TIN. 
By Charles Nollner. 
When a long flask is filled to the top with granulated 
tin, and a concentrated solution of protochloride of tin is 
then poured into it, and kept constantly boiling, large 
bubbles of muriatic gas incessantly escape from the solu- 
tion, which gradually dissolve the tin above the liquid ; 
and in proportion as this happens, an amorphous crust of 
tin separates from the tin-solution on the surface of the 
liquid ; so that if the boihng were continued for fourteen 
days, as much of tlie tin situated above the liquid would 
be dissolved as the solution previously contained. No hy- 
drogen gas is evolved ; it is merely a continuous separation 
and reunion of the elements of the tin-salt, the electro- 
negative constituents of the solution, i. e., the muriatic acid 
and the oxygen of the water combine with the tin situated 
above the liquid, which is there positive, and dissolve it; 
while the protoxide of tin and the hydrogen of the decom- 
posed water, the positive constituents of the solution, pro- 
ceed beneath the surface of the liquid to the tin, which is 
there negative, the hydrogen reducing the protoxide of tin, 
and thus eliminating tin in the form of a bright metallic 
layer. 
If this process is carried out in the cold by placing a bar 
of tin in a concentrated solution of the protochloride, and 
carefully pouring a layer of water upon this, so that the 
bar of tin is situated in both liquids, we very soon observe 
at the place where the two liquids are in contact, the tin 
separate in spicula, frequently from four to five inches long. 
Sometimes it is also obtained in very thin quadratic laminae, 
which readily separate at their centre into four rectangular 
