l8 MAINE AGRICULTURAI. EXPERIMENT STATION. I913. 



carried, however, only 37.47 per cent. Because of the over- 

 weight, the package actuahy contained .90 pound metalhc arsenic 

 soluble in water. Two pounds of the guaranteed composition 

 would have carried only .81 pounds metallic arsenic. 



Orc'hard Brand Arsenite of Zinc Combined with Atomic Sul- 

 phur, made by the Thomsen Chemical Co., Baltimore, Md., was 

 full weight, a five .pound package containing 81.4 ounces of the 

 material. According to the label the active ingredients should 

 be, sulphur from 34 to 40 per cent, arsenic of zinc 25 to 30 

 per cent, soluble arsenic as metallic arsenic .08 to .4 per cent, 

 water 42 to 52 per cent. The sample examined was well 

 within these limits., carrying 40 per cent of water, 8.54 per cent 

 of total arsenic, except that its water soluble arsenic was double 

 the claimed amount, being .98 per cent. The sulphur was 36.6 

 per cent. 



Bowker's Pyrox, made by the Bowker Insecticide Co., Bos- 

 ton, Mass., analysis claimed; lead oxide 17 to 21 percent, cupric 

 hydroxide 2.55 to 3.55 per cent, arsenic oxide 6.75 to 8.43 per 

 • cent, equivalent to metallic arsenic 4.40 to 5.50 iper cent, water 

 soluble arsenic none to .40 per cent, essential inert ingredients 

 61.12 to 69.30 per cent. The sample examined carried 4.98 per 

 cent metallic arsenic and was above the minimum guarantee of 

 4.4 per cent. The package was full weight, containing 16.3 

 ounces for one pound. 



Cooper's Sheep Dipping Powder, M. R. C. V. S. Chemical 

 Works, Berkhamstead, England. Guaranteed to contain 16.7 

 per cent of metallic arsenic in water soluble form. On analysis 

 it was found to carry 8.76 per cent of arsenic, equivalent to 

 36.25 per cent of arsenate of soda. As the goods carried 64 per 

 cent of sulphur there was no possibility of their being as much 

 metallic arsenic as is claimed. There was probably a mistake in 

 calculating the formula in some way. This would probably be 

 an efifective powder, but withall a rather dangerous one on 

 account of the large amount of soluble arsenic w'hich it carries. 



The I. X. L. Poison Fly Paper, claimed to carry 21.6 grains 

 of arsenate of soda. The sample examined was approximately 

 up to that, carrying 20.37 grains. 



Seibert's Poison Fly Paper was guaranteed to contain 5 to 7 

 per cent metallic arsenic in the form of sodium arsenate. The 



