it 
PP pn I Fat a We 4g Yep) a eg a ae oF BY y Soles re tle gl | gee bees 
Hoe oh see ie 
: erystallizes only as a hydrate? Why should we pay so little 
J, M. Ordway on Waterglass. 
regard to analogy as to write Na,Si,H,, and Ga,Si, for sub- 
stances as definite as crystallization can make them, when sod 
and lime are not known to form any other unquestionable basic 
ts? If we attribute to silica a composition similar to that of 
carbonic acid, the monosilicates GaSi, MgSi, MnSi, Gui, and the 
basic silicates Sig,Si, Zn, Si, Mn,Si, and ‘Gu,Si, will be no longer 
unparalleled; and though some minerals will show a composi 
tion unlike that of artificial salts, most of the double silicates 
will have far less strange looking formulas. ; 
the gum-like compounds of acid and base, crystallization 
can take place only when the colloid constituent is reduced to 
sf 
nates only while there is no Jack of alkali. Now if we a 
caustic soda to waterglass, the mixture becomes capable of af 
fording crystals just so soon as the quantity of soda very slightly 
exceeds that of silicic acid, and no sooner. Fair analogical rea 
soning would lead to the belief that then, and not till then, had 
alkali 
causes the evolution of somewhat less heat than before. A far 
. must be an acid salt, and that cannot be its true constitution. 
rials of mixture were made with two thermometers g 
to fifths of a degree Fahrenheit, 
31. 110 g. of a solution containing 47 p. ¢. of NaO.2:37Si0, at 64°4°_ 
F., were mixed with 212 g. of a 10 p. ¢. caustic soda liquor at 64°2°, 80 
as to make NaO.SiO,. The thermometer was raised to 71°4°, making 
a rise of 7:3° F, 
82a. 110 g. of 47 p. ¢. NaO.2-48i0, at 61:5° F. were mixed with 
90 g. of 10 p.c. NaO at 61-7° to form NaO.1-5Si0, or NaO.Si0. The 
thermometer rose to 71-4°, making an increase of 98° F. : 
4. The 200 g. of a at 65-2° F. were mixed with 129 g. of 109. & 
