508 



has been used with some success with wee\dlly beans. Moist 

 heat on account of its tendency to promote the development of 

 molds is rarely available for foods which are to be stored. 



All fumigation methods have the disadvantage of uncer- 

 tainty and while of very great use where the food is soon con- 

 sumed are not advisable where long continued storage is 

 planned. 



It has been found that carbon bisulphide in the proportion 

 of 2 pounds to 1000 cubic feet, kept in tight receptacles for not 

 less than 48 hours will ordinarily sterilize bags of grain, de- 

 stroying even the most resistant. More satisfactory results 

 can be obtained where the receptacle is so tight as to permit 

 the air to be exhausted. 



One serious objection to the use of carbon bisulphide is the 

 vile odor of many of the commercial grades which would utter- 

 ly prevent its use in the home except in some outbuilding used 

 for the purpose. Its fumes are also extremely inflammable 

 and explosive when mixed with air. This is, however, a method 

 widely used and with a high degree of success where absolute 

 sterilization is not required. 



Another exceedingly important method of fumigation em- 

 ploys hydrocyanic acid gas liberated by the action of sulphuric 

 acid on potassium or sodium cyanide in an excess of water. 

 This gas has higher penetrating power and is enormously more 

 poisonous than the carbon bisulphide gas. Even in relatively 

 loosely constructed mills fumigation with the gas produced by 

 1 oz. potassium cyanide and 1 oz. of sulphuric acid in 3 ozs. of 

 water for each thousand cubic feet has given satisfactory re- 

 sults. In closer quarters the dose could be considerably reduced. 

 This method of fumigation requires to be handled with great 

 care and is not generally available in the home on account of 

 the deadly poisonous nature of the potassium cyanide and the 

 resulting gas and the caustic and corrosive nature of the sul- 

 phuric acid. 



Both methods of fumigation may be employed without 

 affecting the germinating properties of seeds. In neither case 



