es great rapidity, the whole round of operations may be carried out 
in a few hours, But while stannate of soda can be readily 
E procured coarse grained, white, and of normal composition, th 
} precipitated potash salt is very fine, artd besides obstinately re- 
taining much of whatever organic coloring matter may have 
been present in the original solution, it is hable to come out at 
last with sounewhat too much or too little oe ay 
2. A crude stannate prepared by heating strongly a mixture of tin, 
caustic potash, and nitrate of potash, was dissolved in twice its weight of 
were thoroughly agi- 
tated with 400 c. c. of alcohol of sp. gr. 0°840, and gave a dense liquid 
deposit measuring 275 c.c. This being in turn treated with 400 c. c, of 
alcohol, yielded 175 c. c. of still denser liquor, A third precipitation 
with 400 c.¢. of alcohol gave a deposit with some solid matter beginning 
pc ree Hees aeer, ok Ai i 
(9 
rig 
i 
o 
Oo 
Ss 
i) 
on . 
° 
=r 
om 
ie 
oO 
c. 
9°) 
no 
ee 
a 
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Q 
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A 
ao 
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= 
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= 
_ So far a weaker spirit had been used so as to allow the impuri- 
ties to remain in solution while the stannate was thrown down. i 
. one ‘ 
ape cos tS hei 
tigger ial {1 ee oe, eae 
round of treatment with alcohol. The hard pressed final product con- 
tained 73 p.c. of dry stannate. Being spread out and exposed _ a 
air for some hours, it lost all smell of spirit, and was then pure and al- 
most exactly normal. “ sce eal 
When greater nicety is required, such a product shou 
dissolved in a little ees than its weight of water and recrystal- 
lized by spontaneous evaporation i vacuo. 
A pole analysis was made of some pure, = on 
transparent, oblique rhombic crystals produced 7 t - asi 
method and dried by pressure in absorbent paper. It show 
Ibslotion etusndon Vabgpeprgrengencnn oe eee 
2 A solution of K Sno.9 saturated at 0° C. bad the sp. gr. 1-64 and contained 
- ol shah icin of K Sn,.. saturated at 0° C. had the sp. gr. 1°74 anid coutalott 
| E Gr meakeg 28 eB f ference’ to the oxyd of tin, we may say that its ola: 
; bility increases as the amount of alkali present is diminished. = 
