17 



The chemicals must be mixed in the following order. Place 

 the water in an earthen jar or wooden receptacle in which the 

 gas is to be generated. (Any sort of metal recepticle is not 

 suitable as the acid will eat it full of holes.) Next add the acid. 

 After the room has been tightly closed with the exception of one 

 door, drop the cyanide in the acid and water and cióse the exit 

 door. Forty minutes to one hour is sufficient time to allow for 

 fumigation. Fumigation with hydrocyanic gas must be cori- 

 ducted with extreme caution as the cyanide is deadly poisonous 

 and the gas is the most deadly gas known. For some individuáis 

 a single full breath of the gas is fatal. Liquid foods or foods of 

 high water content should not remain in a room which is fumi- 

 gated, as the moisture attracts and condenses the gas, forming 

 a poison. 



In other citrus fruit producing countries, hydrocyanic acid 

 gas is used quite extensively for ridding the trees of scales. It 

 is clemonstrated beyond doubt that the operation is not econo- 

 mical for use upon any but the large trees. For this reason 

 and because of the high price of chemicals and the required 

 heavy outlay for apparatus, we scarcely believe that fumigation 

 will be practicable in Cuba in any but the larger groves and in 

 fumigating nursery stock for some time to come. Doubtless the 

 time will arrive when the practice will come into general use 

 for orchard work. The fumigation of all imported nursery stock 

 as well as that distributed locally should be required by law and 

 it is to be sincerely hoped that some such law may soon be 



enacted. 



For those intérested in the fumigation of citrus plants 

 detailed instructions may be had in the following publications : 

 Farmer's Bulletiu 172, Superintendent of Publications; Wash- 

 ington, D. C; Citrus Fruits and their Culture, H. Harold Hu- 

 me.; Bul. 152 University of California, Berkley, Cal. and the 

 publications relating to the subject of the California State Com. 

 of Horticulture, Sacramento, Cal. 



FUMIGATION "WITH SULFUR.— Fumigation with sulfur 

 is a common practice for ridding buildings of vermin and bats. It 

 is also nsed to a considerable extent as a disinfectant. The sulfur 

 either in sticks or powder is placed in a recepticle and set ou 



