28 INSECTICIDES AND FUNGICIDES. 



SLUG SHOT. ^ 



[Serial No. 19524.] 



Composition of Slug Shot. 



Per cent. 



Water of crystallization and hygroscopic 18. 37 



Sand 4. 09 



Sulphur trioxid 39. 65 



Calcium oxid 27. 75 



Copper oxid .58 



Arsenious oxid 1. 58 



Ferric oxid 1. 98 



Sulphur and carbolic acid 4. 00 



Tobacco (by difference) 2. 00 



100. 00 



The sulphur, carbolic acid, tobacco, arsenious oxid, and copper oxid, 

 in so far as they go (about 8 per cent) are of value as either insecticides 

 or fungicides, but the remainder is inert in its action on insects. It is 

 possible that the gypsum present in this compound is used to act as a 

 mitigating agent upon the active substances mentioned above. 



BLACK DEATH. 



[Serial No. 19846.] 



Composition of Black Death. 



Per cent. 



Carbon 17. 11 



Sand 5. 86 



Moisture 10. 18 



Carbon dioxid 12. 39 



Sulphur trioxid 23. 15 



Arsenious oxid .97 



Copper oxid 59 



Ferric oxid .46 



Calcium oxid 24. 97 



Magnesium oxid 5. 03 



100.71 



The only substances present in this compound which have any value 

 as insecticides are copper oxid and arsenious oxid, and these are 

 present in very small quantities. If mixtures containing as small 

 amounts of arsenious oxid and copper oxid as this will kill insects, it 

 would be much better for the consumer to buy a pound of Paris 

 Green and mix it with about 75 pounds of gypsum, thus obtaining 

 76 pounds of the preparation at a cost of about 50 cents, while if it 

 was bought already prepared, it would cost retail about $3.80. 



See correspondence with manufacturers, page 61. 



