Experiment station bulletins. 



B7l 



ARSENATES 



Arsenate of Lead Paste. Ten samples were collected and analyzed. 

 (Mily one sample was found to be below tlie lej^al standard. Sample 155 

 iiianiifactured by the Imperial Chemical Co., Crand Kapids, Mich., con- 

 tained less than the legal amount of total arsenic oxide and more than the 

 legal amount of water and water-soluble arsenic oxide. 



Arsenate of Lead Powder. Thirty-one samples were collected and ana- 

 lyzed. There is no legal standard set for dry arsenate of lead but a stand- 

 ard corresponding to the paste form would be as follows: Not less than 

 25 per cent total arsenic oxide (As.O.,) and not more than 1.50 per cent 

 water-soluble arsenic oxide (As.^Or,). Sample 149 manufactured by the 

 Imperial Chemical Co., Grand Rapids, Mich., is the only one found to be 

 below the standard for total arsenic oxide and sample 153, manufactured 

 by the Corona Chemical Co., Milwaukee, Wisconsin, is the only one found 

 above the standard for water-soluble arsenic oxide. 



Calcium Arsenate. Only two samples of calcium arsenate were found 

 althougli five samples of calcium arsenate with lead arsenate were secured 

 and analyzed. It is interesting to note that in the samples of calcium 

 arsenate the water-soluble arsenic oxide is greater than 1.50 per cent 

 while in the samples containing an admixture of lead arsenate the amount 

 of water-soluble arsenic oxide, with one excei^tion, is less than one-lialf 

 of one per cent. 



LEAD ARSENATE ( PASTE) 



No, 



382 



112 

 161 



408 

 134 

 364 

 411 

 155 

 372 

 381 



Maniifacturer. 



Ansbacher Insecticide Co,. 

 New Yorii. New York 



Dow Chemical Co.. Midland. 



Mich 



Dow Chemical Co., Midland 



Mich 



Dow Chemical Co,. Midland. 



Mich 



Grasselli Chemical Co,. 



Cleveland. Ohio 



Cirasselli Chemical Co.. 



Cleveland. Oliio 



Grasselli Chemical Co,. 



Cleveland. Ohio 



Imperial C'hemical (^o.. 



Grand Rapids. Mich 



Fred L, Lavenburg. New 



York. N. Y 



Slierwin-Williams Co,. Cleve- 

 land. Oliio 



Mo's- 

 tiire. 



51.20 



50. 10 

 32.00 



48.80 

 48 60 

 44 . 33 

 40.20 

 54.20 

 46 29 

 49.88 



Lead oxide 

 rbO 



32.2.-. 

 33.8s 

 31.30 

 39.4(1 

 32.7 1 

 32 0.'. 

 36.21 



.Xrscntr oxide AsiOi 

 Total. Soluble. 



Foimd. Ouar. 



% 

 15.42 



10.27 

 22.03 



1 6 07 



I ti 09 



17 04 



IS (;o 

 10 98 



II 29 



12 :'.s 



Found. I Guar. 



0.50 



75 

 75 



50 



1 00 



