30 INSECTICIDES AND FUNGICIDES. 



WHITE ARSENIC. 



[Serial No. 22286.] 



Composition of White Arsenic. 



Per cent. 



Sand 0. 04 



Moisture 12 



Arsenious oxid 99. 16 



99.32 



This is an excellent full strength sample of White Arsenic, and could 

 be used with good effect along with lime in preparing homemade cal- 

 cium arsenite. 



ROUGH ON RATS. a 

 [Serial No. 20482.] 



Composition of Hough on Rats. 



Per cent. 



Fine sand 1. 59 



Moisture 20 



Arsenious oxid 71 . 83 



Barium oxid 20. 22 



Carbon dioxid 5. 81 



99.65 



This mixture contains as its active poisonous constituents arsenious 

 oxid and barium carbonate, and will be apt to serve the purposes for 

 which it is intended. Great care should be taken not to leave any 

 of this compound carelessly around a house, since it might be stirred up 

 with the dust, breathed by persons, and finally cause arsenic poisoning; 

 also, in the presence of organic matter, the same action might take 

 place, as has been noted in the case of arsenical wall papers, resulting 

 in the formation of a very poisonous gas, arsine. 



ROYAL ROACH POWDER. 



[Serial No. 22290.] 



Composition of Royal Roach Powder. 



Per cent. 



Borax 30.94 



Arsenious oxid ft 73 



Arsenic oxid& 4. 69 



Some calcium. & 

 Some dyestuff. & 



The remainder appears to be Persian Insect Powder or pyre- 

 thrum. 



This mixture may be effective in killing and driving away roaches, 

 ants, etc., but the advisability of scattering it around indiscriminately, 

 as is usually done with roach powders, is very doubtful, since it 

 contains arsenic, which might rise with the dust of the room, and 



See correspondence with manufacturers, page 62. 



b Corresponding to about 12 to 13 per cent London Purple. 



