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CIRCULAR 3 7 3, U. S. DEPARTMENT OF AGRICULTURE 



siderable area is discolored. Figure 18 shows two stages in the pro- 

 gression of cyanide injury, 3 days having elapsed between the taking 

 of the pictures. Another feature which characterizes cyanide in- 

 jury is the fact that the flesh beneath the injured skin is usually hard 



Figure 17. — Bananas injured by fumigation with hydrocyanic acid (5 pounds per 1,000 

 cubic feet) : A, Hand exposed to fumigant for one-half hour; B, hand exposed to 

 fumigant for 4 hours. Photographs taken 5 days after fumigation. 



and pithy. In the case of a banana severely injured (fig. 17, B) 

 by a heavy dosage of hydrocyanic acid the fruit does not ripen and 

 remains hard long after untreated fruit has become overripe. 



Figure 18. — Progressive stages in injury to bananas caused by fumigation with hydro- 

 cyanic acid (5 pounds per 1,000 cubic feet for one-half hour) : A, Hand showing 

 slight injury ; B, the same hand, 3 days later, showing how the injury has spread. 



It must be remembered that all the fruit under discussion was 

 subjected to a dosage of 5 pounds of hydrocyanic acid per 1,000 

 cubic feet. The difference between this concentration and 6 ounces 

 per refrigerator car is apparent, and it has been previously pointed 



