J. M. Ordway on Waterglass. 163° 
and so produces the opacity of the glass. Stein however found 
besides, 1:5 per cent of lime and 2°3 per cent of bone earth, in 
waterglass quite milky. : 
But the real value of any sample can be ascertained only by 
a chemical examination, and as the analysis is liable to some 
Peculiar chances of error, it may be well to point out a few of 
the peculiar precautions to be observed. _ 
_ In th e of a dry glass, especial pains must be taken to 
insure the solution of everything that water will take up,—a 
Matter requiring some labor and time. For determining the 
require. 
stirred 
* Liebig and Kopp’s Jahresbericht for 1856, p. 54. 
t Wagner's A aeeestaht p. 244. 
