5 



gether, tlie precipitated coloring matter being allowed to 

 settle. 



Paris Green is normally a bright crystalline powder, 

 insoluble in water, but changing in color when boiled with 

 water for some time. According to Ehrmann, the composi- 

 tion of pure Paris Green is as follows : 



Copper oxide 31.29 



Arsenious acid 58.G5 



Acetic acid ' lO.OG 



The purest grades of Paris Green, however, shoAv at least 

 slight variations from the proportions given above, and it is 

 quite difficult to fix an absolute standard for the composition 

 of products of this character. 



Paris Green, which is intended for use as an insecticide, 

 however, should contain at least -lO per cent, of combined 

 arsenious acid, and any purchasers of this article who are 

 in doubt as to its purity or quality can have the same tested 

 by forwarding a sample to this Laboratory. 



The following is the result of the examination of the sam- 

 ples of Paris Green received at this Laboratory : 



Arsenious acid. 

 No. 1. From Hale Co., forwarded by Mr. B. 



L. Garber ". 55.42 



No. 2. From Wilcox Co., forwarded by Mr. 



S. M. Cathcart 55.01 



No. 3. From Montgomery, forwarded by 



Dept. of Agriculture 59.71 



No. 4. From Montgomery, forwarded by 



Dept. of Agriculture 53.13 



No. 5. From Montgomery, forwarded hj 



Dept. of Agriculture 57.38 



'No. 6. From Eimer & Amend, New York .... 54.15 

 No. 7. From Tallapoosa county none. 



Samples one to six inclusive, possessed the bright green 

 color characteristic of a genuine Paris Green, and their 

 mechanical condition was all that could be desired. 



