New Yorx AcricunturAL Experiment Station. 243 
4. The solubility of Paris green in strong ammonia is a fair test 
of purity, so far as concerns the addition of white arsenic and 
insoluble adulterants, like barium sulphate, calcium sulphate, ete. 
In the table above we have indicated those samples that dissolved 
easily and completely in strong ammonia, making a perfectly clear 
solution without sediment. These samples were free from white 
arsenic. Fifteen samples dissolved satisfactorily, while nine sam- 
ples did not dissolve completely at once, but only on standing for 
a considerable time, and even then traces remained undissolved. 
5. In general, it may be said that the results of our work in- 
dicate a very satisfactory condition as to the purity of the Paris 
green in the market. They do not justify the widespread belief 
that Paris green is extensively and seriously adulterated. In every 
instance the arsenious oxide considerably exceeds the legal require- 
ments. The only material that we have found used as an adulter- 
ant is white arsenic and this in only one or two cases. In not a 
single case have we found such materials as sulphates of barium, 
calcium, ete. 
6. The color of Paris green is changed to such an extent by 
addition of white arsenic or other similar materials that one can 
usually detect an adulterated article by its appearance. Paris 
green of good quality is intensely bright green and uniform. 
When adulterated, the green loses something of its intensity and 
is grayish green and is not always uniform. 
EXAMINATION OF MISCELLANEOUS INSECTICIDES. 
PARAGRENE. 
Two samples of this material were secured, one at Jamestown 
and one at Geneva. ‘One sample contained 43.34 per ct. arseni- 
ous oxide and 18.08 per ct. copper oxide; and the other 52.30 
per ct. arsenious oxide and 21.64 per ct. copper oxide. The ar- 
senic is present in combination with calcium as calcium arsenite 
to some extent. The material is a proprietary article and is not 
put on the market as a Paris green. From the results obtained 
