28 Hl. P. Armsby—Absorption of Bases by the Soii. 
Highty grams of airdry aluminum hydrate were dissolved 
in a strong solution of soda (containing about 200 grams 
NaOH), the solution was diluted largely, and to it were added 
about 310 ¢.c. of commercial water-glass, containing 91 grms. 
siO,. A bulky, flocculent precipitate resulted which subsided 
readily and could be washed by decantation without much dif- 
ficulty. The washing was continued till the washings showed 
no alkaline reaction, the precipitate collected on a filter and 
dried at 100° C. till it seemed dry to the touch. It was then 
pulverized, brought upon a filter, washed till the filtrate gave 
no precipitate with the solution of calcium chloride used in the 
experiments, and again partly dried at 100° C. 
An analysis gave :— 
Tous 26100? Ooo ooo 39°94 
MOPY BUMMER VS ee ee 60°06 
100°00 
The dry substance contains :— 
RIE aes: is Sages ase 48°42 
Al,O, —-——— ee ew lm ee ee 2S 16 
NA esas eee 14°20 
Ree ee skl egos pot ee 14°13 
99°91 
A neutral solution of calcium chloride was also a by 
dissolving fused CaCl, in water, acidifying with HCl, and neu- 
tralizing with CaCO,. 1 ¢.¢. contained the equivalent of 
001683 grams CaO. . o é 
Varying portions of the air-dry silicate were digested in 
closed flasks with the above solution diluted to five, ten, or 
twenty times its volume exactly as in the experiments with 
soil. The mixtures stood three days at ordinary temperature 
with frequent shaking, and then in 50 c.c¢. of the liquid the 
lime was precipitated as oxalate in the usual way, and weighed 
as oxide. The result calculated on the whole quantity of the 
solution and subtracted from the amount of tine originally 
present gave the absorption. The results in every case are ex- 
ressed as CaO, as is also the strength of the solution employed. 
he following are the results. 
Nos. CaO in 1 ¢.c.of sol. We. of silicate. Vol. of solution. | Absorption. 
1, 0°003366 grms. 40 grms. 200¢.c. *[0°6732 grms.] 
& 7coes. 20 . mn 05952 “ 
Os. ee ey 10 we oe 04172 “ 
We Seen 5 ad ee 0°2432 “ 
Ge re ee 2°5 x te Oile7s * 
septs Cer 1°25 . <a 00680 “ 
7 eee o625 = ™* ole 00328 “ 
hence 03125 * “'s 070164 “ 
ef 
