352 J. M. Ordway on Waterglass. 
common article of manufacture, and competition has reduced the 
rice to less than that of Peruvian guano. Indeed were there a 
arge demand, a silicate of soda suitable for manure could be 
made from the sulphate and sold in this country for two cents a 
pound, and yet yield a liberal profit to the manufacturer. 
ass 1s used in solution, it ought to be applied to the 
growing crops by frequent waterings. But perhaps the better 
way would be to spread the finely ground, dry silicate mixed 
with other manures, and thus supply to the soil a material similar 
to its feldspathic ingredients, but far more susceptible of decom- 
position. One or two agricultural experiments do not suffice to 
establish any particular point, and we have as yet too few ac- 
counts of the effects produced by using silicate of soda, to enable 
us to decide as to its real practical value to the farmer. 
There is another application in which waterglass acts as a pur 
veyor of soluble silica. According to Kuhlmann common me 
mortar may be rendered hydraulic by the addition of a few per 
cent of dry, pulverized silicate of potash or soda, and poor ¢ 
ments can, be the same means, be made equal to the best. A 
solution of waterglass will not answer the purpose so well, be- 
cause it sets before the mortar can be got into its place. Still 
recommends both the fine powder and the solution. 
He even attributes the peculiar character of hydraulic cements 
the alkaline silicate naturally present in them, but his views 
have not been fully substantiated. ace 
In the dissolved silicates we have an alkali whose causticity 
is blunted by a very feeble acid, and their similarity in t Te- 
spect to the oleostearates, suggests their employment in the place 
of soap. Waterglass has indeed great cleansing power, — 
sive, as well.as the solvent power, comes into play, and in many 
instances that soap is found most suitable that froths most. Wa 
ing or scouring, than a caustic alkali, since it does not pa eer’ 
ate of 
in any respect. For cleaning paint however the silicate 
ing establishments and in laundries, but though some 8a 
does well enough, the reports are generally unfavorable.* 
be ; * Wagner's Jahresbericht, iv, 172. 
