350 J, M. Ordway on Waterglass, 
As a thick solution of waterglass dries at first to a glassy, m- 
penetrable varnish, Griine has suggested its employment as a 
resist in calico-printing ;—that is, as a substance to cover those 
arts of the cloth that are to remain white, and prevent them 
from imbibing the dyeing liquor. But hot water dissolves the 
silicate rapidly, and hence such a resist can answer only when 
the printed cloth is to be immersed for a very short time in cold 
dyeing baths, 
In the manufacture of porcelain wares, pastes are sometimes 
used that are devoid of plasticity and requires the addition of 
some glutinous material to give them sufficient cohesiveness to 
allow them to be moulded. For such pastes “ mineral glue” 
would probably do better than a destructible mucilage. 
2. In fusibility and fluxing power waterglass greatly resembles 
borax, and in some cases may well replace this expensive salt. 
The iron hoes employed in stirring the fused silicate during 1ts 
preparation are kept remarkably clean and bright by the melted 
ass 
ther into the body of the ware than any flux insoluble in water, 
it should take a firmer hold. It is said however that Leibl’s am 
has been ‘tried with unfavorable results, but it is quite poss!b!¢ 
that the experiments were not properly conducted. _ 
Though sulphate of soda is exceedingly cheap in this we 
and sulphate of potash, abundantly obtained in refining pearlas 
finds sale only at a very low price to alum makers, 
manufacturers generally employ only the carbonates. | 
long sought to produce purified alkaline silicates that might ei 
nomically replace the carbonates in making the better saat 
of glass, but have been met by a hitherto insurmountable i 
culty. The alkaline sulphates can be decomposed by silica 6” 
* Wagner's Jahresbericht, iii, 137. + Id, ii, p. 211. 
