174 J. M. Ordway on Waterglass. 
chlorid of sodium, but made a slightly opaline solution with water, thus 
showing the presence of a trace of metastannate. 
Crystals lag from the press give a clear and complete solu- 
tion ; and as a trifling amount of adhering alcohol is seldom of 
any sae it is best to expose the pressed cake to the air 
as little as 
When the product ‘i is freed from mother liquor by absorption 
and careful drying it appears to have the composition NaQ, 
Sn0,, 3HO. 
To ‘get pure and clean crystals for an exact determination of 
the water a strong solution of the preparing salt was 
with icmp of baryta, and as much alcohol was added to the fil- 
rate as it would bear without turning milky. In two days there 
gathered around the sides and bottom of the bottle a thin, hard 
coating of transparent crystals, which were detached and ressed 
in absorbent paper till they appeared dry, but not at all 1 efilo- 
* Storer, in his Dictionary of Solubilities, under the heads “ Stannate of Potash” 
and “Stannate of Soda,” has collected - ny all that is known ronperting. 3 these 
salts. We are there told that, according to Fremy, stannate of soda is much more 
soluble i ino cold than in warm Beige To tase this ma non hess to reduce wn iomatee 
b e made the following e: 
L - oe solution was as prepared by ge mene cuatae. water with an ex- 
of the et a ed with snow. It was ° 
filtered in a pen also aig a 0° The yond ab warmed to 155° C. had the 
sp- gr. 1472. It contained 3271 es c. 0 
TI. A saturated solution made in a room kept = 10°C, had the sp. gr. 17448, and 
contained 81 p. c. of the dry ey or 39 p.c. of Na Sn H;. 
Ill. A saturated solution sagem made in a flask ony in ery 4 at 20° C. oe at 
15°5° C. it had the sp. gr. 1-438. It contained 30- of NaSn. So 100 parts 
water dissolve 67°4 ot of the crystals, Na gn at at re C.; and at 20° C., only 
61°8 parts, or nine-tenths as much. 
Stannate of potash shows no such anomaly, but its solubility is somewhat in- 
IV. At 10°C. a saturated solution was made with crystals of K SnH, formed by 
spontaneous evaporation in vacuo, that fa a 1618 and contained 42°3 p. ¢ 
ot Ko 
a? A saturated solution made at 20° C. had the 1-627 and contained 43 
ani wes ae 
