176 J. M. Ordway on Waterglass. 
49-430 p. c. of stannic acid, and 80-704 p. c. of potash. If we 
call the equivalent weight of tin 59, these proportions would 
make KSnH 33. he true formula must therefore be KO.Sn 
O, .8HO. 
The specific gravity of these crystals was found to be 3°197. 
Metastannate of Potash—When a dilute acid is slowly, and 
with constant stirring, dropped into a cold solution of normal 
stannate of potash, there is no permanent precipitation till more 
than three-fourths of the alkali is abstracted. The stannate thus 
robbed of its base, remains perfectly dissolved, but has acquired 
different properties. cohol now gives with it not a liquid or 
paper till it became a transparent, exceedingly shrunken mass containing - 
79 p.c. of KSn,.,. This easily dissolved in twice its weight of water. : 
: 
nate containing 59 p. c. of KSn,.,- This dissolved in four times its own 
weight of water to a faintly opaline liquid. : 
5. Some of the solution of 3 was diluted and cautiously treated with 
sufficient nitric acid to neutralize one-third of the remaining potash. a 
despoiled metastannate was then precipitated with alcohol. The final = 
product consisted of KSn,,., H, and was readily soluble in water. 
ery gradually indeed; otherwise the pulp itself will pass 
at the pores of the cloth. 
phate of 
solution 
