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NITRATES AND CHLORATES. 
ART. XL VI II. — A MODE OF DISCRIMINATING BETWEEN NI- 
TRATES AND CHLORATES IN VERY DILUTE SOLU- 
TIONS. 
By M. Vogel, Jr., of Munich. 
When a solution of nitrate of potassa is rendered blue by 
the addition of a few drops of tincture of litmus, and concen- 
trated sulphuric acid is added, the tincture is reddened by 
the sulphuric acid, and by the nitric acid set free, but its color 
is affected in no other manner. On the contrary, a solution 
of chlorate of potassa, rendered blue by the tincture of litmus, 
is totally decolorised by the addition of concentrated sulphuric 
acid; a result by which the chlorate may be essentially dis- 
tinguished from the nitrate. 
To ascertain the extent to which the chlorate may be di- 
luted, without losing its power of decolorising litmus, I dis- 
solved one part of this salt in thirty-two parts of water. The 
colour of the litmus instantly disappeared on the addition of 
concentrated sulphuric acid. The same was the case when 
the salt was dissolved in sixty-four parts of water; but with a 
solution in eighty parts, the color of this litmus was not de- 
stroyed. 
The decoloration of tincture of indigo took place with a 
much weaker solution of chlorate of potassa; for a solution 
of one part in 500 of water retained the power of destroying 
the color by the aid of sulphuric acid. 
This mode of discriminating between nitrates and chlorates 
in dilute solutions, offers this advantage, that it affords certain 
results from producing the decoloration of tincture of litmus, 
even when the chlorates are accompanied by other salts. 
With this in view, I added many other salts, principally 
chlorides, to the solution of chlorate, without preventing the 
loss of colour. 
