SWIFT'S LEAD ARSENATE WHITE AKSENOID. 



SWIFT'* LKAI) ARSENATE. 

 [Serial No. 19626.] 



Cotnpotitiojn of Swift's Lead Arsenate. 



Per cent. 



Moisture 1. 39 



Lead oxid" 58. 90 



Arsenic oxid" 25. 62 



Organic 13. 00 



98.91 



The organic portion of this substance consists of dextros and dex- 

 trin, showing that glucose sirup has been added to cause the lead arse- 

 nate to adhere to the foliage. 



This compound is the least soluble of all the arsenical insecticides 

 tested, and consequently is not liable to scorch the foliage. It has been 

 used as an insecticide with good results. 



WIIITK 



[Serial No. 22287.] 



Competition <>f }\hi/<'Arsenoid. 



Per cent. 



Moisture ............................................ 1. 90 



Sand ................................................. 38 



Chlorine ............................................ 4. 46 



Carbon dioxid ....................................... 8. 88 



Arsenic oxid ......................................... 1. 13 



Arsenious oxid ....................................... 33. 67 



Sodium (joined with part of chlorin) .................. 1. 25 



Barium ( to join with part of the chlorin) .............. 4. 89 



Barium oxid. . . 42.19 



98.75 



Arsenious oxid dissolved by cold water 33. 67 



Large amount of barium salts also dissolved by cold water. 



The two compounds which give this substance any value as an insec- 

 ticide are the arsenious and arsenic acids. Since, however, all of the 

 arsenic is present in a soluble condition, an application of this mixture 

 to the foliage would burn it badly, consequently the use of this insec- 

 ticide can not be recommended. It is understood that the results from 

 this mixture have been so unsatisfactory that it has been withdrawn 

 from the market. One point in connection with White Arsenoid which 

 has not been mentioned in any of the State experiment station reports 

 on the subject is the probable toxic effect of barium in a soluble con- 

 dition on plants sprayed with it. 



"The methods for determining PbO and As. 2 O 5 give rather low results. 

 & See correspondence with manufacturers, page 59. 



