A436 REpoRT OF THE INSPECTION WorRK OF THE 
DISCUSSION OF RESULTS OF CHEMICAL ANALYSIS. 
1. Total arsenious oxide.— In the 44 samples of materials sold 
as paris green and examined by us the amount of arsenic 
equivalent to arsenious oxide varies from 55.39 to 61.40 per ct., 
and averages 57.10 per ct. So far as the total arsenic content is 
concerned, the amount found indicates a high quality of paris 
green. The variation is about the same as last year and, except- 
ing four samples, is within surprisingly narrow limits. Were 
the total amount of arsenic present in paris green the only point 
to be considered, the quality would be regarded as very satis- 
factory, but we must consider at the same time the amount of 
water-soluble compounds of arsenic present in paris green. 
2. Water-soluble compounds of arsenic.— The presence of 
water-soluble arsenic in paris green is seriously objectionable 
owing to the fact that soluble arsenic compounds injure foliage. 
Hilgard, of California, states that in the dry climate of Cali- 
fornia paris green injures foliage when it contains an equivalent 
of more than 4 per ct. of arsenious oxide in the form of soluble 
arsenic compounds. The water-soluble arsenic most commonly 
occurring in paris green is in the form of arsenious oxide, com- 
mercially known as common white arsenic. 
The water-soluble arsenious oxide varies in the 44 samples of 
paris green examined from 0.61 to 1.35 per ct. and averages 1.01, 
which is far below the limit of harm prescribed for use as an 
insecticide and the limit fixed by law. 
3. Copper in paris green determined as copper owvide.— The 
amount of copper expressed as the equivalent of copper oxide 
varies in the 44 samples of paris green examined from 27.03 to 
30.79 per ct. and averages 29.41 per ct., which is about the same 
as in preceding years. 
4. Amount of arsenic oxide in combination with copper.— The 
law relating to paris green in this State was amended in 1901 
so as to correct certain defects existing in the original law with 
reference to the definition of paris green. The original law 
required that paris green should contain the equivalent of 50 
per ct. of arsenious oxide. This provision was needlessly low, 
and was also open to the very serious objection that it per- 
