CHEMICAL CHANGES IN" CALCIUM AKSENATE. 



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Fig. 50.— Average results with AS-6, BS-6, CS-6, FS-6, HS-6, IS-6 (paper-lined veneer drums). 



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Fig. 51. — Effect of container on absorption of carbon dioxid. 



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Fig. 52. — Effect of container on water-soluble arsenic oxid. 

 SUMMARY. 



Commercial calcium arsenate in the dry powdered form manufac- 

 tm-ed for insecticidai purposes absorbs carbon dioxid slowly from 

 the atmosphere during storage and increases in water-soluble arsenic- 

 oxid content, unless it is packed in containers that are practically 

 air-tight. The rates of these changes show a close relationship and 

 depend largely upon the type of container in which the material is 

 packed. 



TJie absorption of carbon dioxid is the first change noted. This 

 is followed ;\ little later by a rise in the water-soluble arsenic oxid 



































































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