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SPURIOUS CHEMICALS. 327 
posed, then as the heat is in- rianic acid. The vapor does 
creased, burns with a lumin- not readily inflame, and the 
ous flame, and emits a very odor emitted is not offensive, 
offensive odor. 
The residue of oxide of iron is the same in both speci- 
mens, namely, twenty-five per cent., and the acid originally 
present is organic. 
Where mere adulteration is practised, the detection of the 
fraud is much more difficult than it is in the cases to which 
we have hitherto alluded, the cupidity of the manufacturer 
having fortunately, in these cases, blinded his discretion, so 
that a speedy exposure of the practice was inevitable* 
About three years ago, as we find from the Journal de 
Pharmacies much of the valerianate of zinc met with in 
Paris, was found to have been made with butyric acid, 
instead of valerianic acid. The butyrate thus substituted 
was of a more beautiful and crystalline appearance than the 
true valerianate, but it did not essentially differ in character, 
and the detection of the fraud, by satisfactory tests, was not 
easily accomplished. A paper was published on the sub- 
ject by Messrs. Laroque and Huraut, in which they re- 
commend the use of a concentrated solution of acetate of 
copper for distinguishing valerianic from butyric acid. In 
the use of this test, however, it is necessary, in the first 
place, to eliminate tha acid by adding sulphuric acid to the 
salt and separating the volatile acid by distillation. When 
butyric acid is added to the concentrated solution of acetate 
of copper, a blueish white precipitate is immediately form- 
ed ; but on adding valerianic acid in like manner, there is 
no immediate appearance of precipitation or turbidity of 
the liquid, but on shaking it, oily drops of a greenish color, 
separate, partly rising to the surface and adhering to the 
sides of the vessel, and partly falling to the bottom. These 
oily globules consist of anhydrous valerianate of copper, 
which retains this condition sometimes for twenty minutes 
or more, but it ultimately becomes hydrated, and then forms 
a blueish green crystalline powder. 
