﻿10 BULLETIN 1149, U. S. DEPARTMENT OF ACIIUTLTI l:K. 



Tahle 3. — riti/sical (j/>cts of hydrocyanic acid yax on fruits and vegetables. 



Product. 



Effect of hydrocyanic acid. 



Product. 



Effect of hydrocyanic acid. 



Apples 



None. 



Deterioration very much has- 

 tened. 



Slight yellowing of the pulp; 

 some "darkening of the epi- i 

 carp. 



None. 



Do. 

 Some wilting and yellowing. 1 ' 

 None. 



Severe wilting.* 

 None. 



Do. 



Do. 



Do. 

 Decided softening. 

 None. 



Do. 

 Immediate and severe wilting. 1 ! 

 Softening. 

 None. 

 Darkening of the epicarp. 



Muskmelon 



Oranges 



Parsnips 



Peas 



Decided softening. 

 None. 



Do. 



Do. 



Avocadoes 





Do. 

 Do. 



Beans (green, 

 string). 



Pears 



Peppers (green) . . 



Plantains 



Potatoes (sweet) . 

 Potatoes (white). 

 Salsify 



Squash 



Tangerines 



Tomatoes 



Turnips 



Watermelons 



Darkening of the epicarp. 

 None. 

 Do. 





Decided softening of the pulp 

 and browning of the epicarp. 





Celerv 



Corn(green, sweet) 

 Cucumbers 



! Do. 



i Do. 



Do. 





Do. 





Decided softening and severe- 

 wilting. 1 



Grapefruit 





Do. 





Do. 



Mammee apples. . . 



Do. 







1 Deterioration was so serious that the product was not marketable. 



Some of the fumigated products show a tendency to speedy decay, 

 probably because of a reduction of their natural resistance to putre- 

 factive organisms (PI. I). This is particularly noticeable in the case 

 of the avocado. Kefrigeration does not seem to prevent the disin- 

 tegration to any great extent. 



No very direct relation seems to exist betw r een the quantity of 

 hydrocyanic acid absorbed and the damage to the tissues. Green 

 peas and string beans both absorbed large quantities and yet show r ed 

 no deterioration. On the other hand, mameyea, pears, and musk- 

 melons contained comparatively small quantities but deteriorated 

 greatly. 



Although Schmidt (21) reports severe deterioration of peaches due 

 to fumigation, the lower concentration of gas in the experiments here 

 reported gave no such effects. 



SEEDS AND FLOUR. 



Experiments with seeds and flour were undertaken to determine 

 the following points: (a) The quantity of hydrocyanic acid absorbed 

 during fumigation: (b) the rate at which it is dissipated on storage; 



(c) the effect of evacuating the chamber several times after fumiga- 

 tion on the quantity of hydrocyanic acid retained by the product; 



(d) the relation of the concentration of the fumigant to the quantity 

 absorbed. 



Navy beans, white field corn, cowpeas, wheat, and flour were tested. 

 Sacks containing; about 15 pounds of each were fumigated with the 

 dosage indicated, bv a modification of the method of Sasscer and 

 Hawkins (20). 



In the first series of experiments the products were put into the 

 fumigation chamber, and air was pumped out until the vacuum 

 gauge registered 26 inches. The hydrocyanic acid gas was then 

 introduced, allowing 5 minutes for generation and 5 minutes for 

 washing the gas from the generator to the fumigation chamber, after 



