J. M. Ordway on Waterglass, 353 
Patents have been obtained for soaps containing an admixture 
of silicate of soda, but until we have some proof that there is 
really anything to be gained by using such soaps, they are enti- 
tled to em & passing notice. J have made experiments to deter- 
mine whether caustic soda could be economically made from the 
silicate, and the answer was decidedly in the negative. 
5. Silicate of soda, on account of its chemical relations, has 
come into general use as a substitute for phosphate or arseniate 
of soda in dunging printed calicoes. This, the most important 
of all the applications, was patented in England by Jiger in 
1852. The silicate by itself, however, was found to be too alka- 
line, and liable to dissolve away the aluminous mordants. Prob- 
ably the article tried by many was not silicious enough, for if 
used alone, it ought to contain at least two equivalents of silica 
to one of soda. But such asilicate is very hard to dissolve, and 
what is prepared by chemical manufacturers, is commonly a ses- 
quisilicate. Indeed Jiiger himself prescribes such proportions as 
would form a sesquisilicate. In 1854 Higgin introduced a great 
inprovement by substituting for waterglass the highly volumin- 
ous lime silicate formed by adding to silicate of soda, in the 
dunging vat, a sufficient quantity of chlorid of calcium to effect 
complete double decomposition. This plan renders it perfectly 
© to take the easily dissolved sesquisilicate of soda; and now 
Waterglass has almost entirely superseded other dunging mate- 
‘als, being cheaper than any other substance, and in most cases 
slving perfect satisfaction. It is possible that in those few in- 
stances in which'it has been rejected, due attention to the hey 
of the articles employed, would remove all difficulties. The fact 
that the alkaline silicates dissolve the protoxyd of iron, has be 
pratooked, and the nine not always take pains 
peroxydize all the iron in the mass. 
a: known an instance in which a lime salt was used, that 
Ppened to contain tarry matter and iron, and some pieces of 
~ cloth dunged with the mixture came out of the dyeing md with 
mixture. And then again commercial muriatic acid often con- 
tains a reducing agent, 
With chalk, which is 
Moval of every trace of iron. J’ure salts of zinc, magnesi 
