10 BULLETIN 1149, U. S. DEPARTMENT OF AGRICULTURE. 
Table 3. — Physical effects of hydrocyanic acid gas 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- 
carp. 
None. 
Do. 
Some wilting and yellowing. 1 
None. 
Severe wilting. 1 
None. 
Do. 
Do. 
Do. 
Decided softening. 
None. 
Do. 
Immediate and severe wilting. 1 
Softening. 
None. 
Darkening of the epicarp. 
Muskmelon 
Onions 
Oranges 
Parsnips 
Decided softening. 
; None. 
Do. 
1 Do. 
Avocadoes 
Bananas 
Peas 
Do. 
Peaches 
Do. 
Beans (green, 
Pears 
Darkening of the epicarp. 
None. 
Do. 
string). 
Beets 
Peppers (green) . . 
Pineapples 
Plantains 
Cabbage 
. Decided softening of the pulp 
and browning of the epicarp. 
Carrots 
Potatoes (sweet) . 
Potatoes (white) . 
Salsify... 
Celery 
Corn(green, sweet) 
Cucumbers 
Do. 
Do. 
Do. 
Eggplant 
Squash 
Strawberries 
Tangerines 
Tomatoes 
Turnips 
Watermelons 
Do. 
Grapes 
Decided softening and severe 
wilting. 1 
Grapefruit 
Lemons 
Do. 
Mameyea 
Do. 
Mammee apples. . . 
Mango 
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. Refrigeration does not seem to prevent the disin- 
tegration to any great extent. 
No very direct relation seems to exist between the quantity of 
hydrocyanic acid absorbed and the damage to the tissues. Green 
peas and string beans both absorbed large quantities and yet showed 
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 
