8 BULLETIN 916, U. S. DEPABTMEXT OF AGRICULTURE. 
when jarrecl. It is considered highly important to call the attention 
of growers and shippers to this point, since under some circumstances 
it would be entirely possible that a lot of potatoes or eyen other prod- 
ucts might be undercooled considerably below the freezing point and 
escape injury if they remained undisturbed till their temperature was 
above the freezing point. If it should be found necessary to moye 
such a lot in order to protect them from further lowering of the 
temperature, this should be very carefully done, haying in mind the 
clanger of freezing as the result of jarring or jolting. These state- 
ments seem justified and are supported by the results brought out by 
the following experiments, which were conducted to determine the 
amount and character of the disturbance necessary to cause freezing 
when different varieties of potatoes are held at temperatures between 
28° and 25° F. The same seven standard varieties before named were 
used in these experiments. 
EXPERIMENT NO. 1. 
Duplicate lots of potatoes, consisting of a single specimen of each 
variety, were held between 26° and 27° F. for 5J hours. Then each 
specimen in one lot was dropped from a distance of 4 feet to the 
concrete floor. After IT hours from the time they were dropped, 
both lots were removed and held at ordinary room temperature 
several hours before they were cut open. In the check lot only the 
Irish Cobbler and the American Giant were injured. All specimens 
in the treated lot were not only badly bruised, as might be expected 
from the rough treatment, but they were all frost injured, as was 
shown by extensive blackened vascular areas of the blotch type. 
(PL I.) Xone of the potatoes were frozen hard enough to cause 
collapse of the tissues. 
EXPERIMENT NO. 2. 
Duplicate lots of one potato of each variety were held at 28° F. for 
22 hours. One lot was then dropped as before and left for three 
hours. Both lots were then removed. As before, at the lower tem- 
perature all the dropped potatoes were bruised and showed extreme 
freezing injury. In the undisturbed check lot only the Irish Cobbler 
was injured. 
EXPERIMENT NO. 3. 
Duplicate lots of one potato of each variety were placed at 28° F. 
for 24 hours. Each specimen from one lot was dropped from a dis- 
tance of 2 feet, and after another 24 hours all were removed. On 
the usual examination it was found that these potatoes were badly 
bruised and showed extensive injury, as before, except the American 
Giant and Spaulding Xo. 4 varieties, which showed no frost injury 
and were not bruised. 
