MARKETING LETTUCE 19 
refrigeration." and many shipments of lettuce are made in this way. 
During recent years many car lots from the Western States have 
broken ice scattered over the top layer of crates in addition to the 
crushed ice within the packages. There is considerable controversy 
over the real merits of this practice, however, and the department is 
now making an extensive study of the whole subject of "body icing." 
The use of salt in the bunkers is becoming increasingly popular 
in some sections of the West. The purpose of adding salt to the 
ice is to obtain lower temperatures within the car and to obtain them 
more quickly than is possible by the use of ice alone. 
PRECOOLIXG AXD STORIXG 
In some producing sections where cold-storage facilities are avail- 
able, lettuce is often precooled by placing the packed containers 
in the storage house for short periods before loading at a temper- 
ature of 30° to 32° F. Thorough cooling by this method often re- 
quires several days. On the other hand it is not considered advisable 
as a rule to delay shipment longer than a week or two on account 
of the increased likelihood of loss by decay. Lettuce held for longer 
periods usually should be moved only to near-by markets. 
Some shipments of precooled lettuce have been made in an experi- 
mental way in an effort to determine the advisability of precooling 
without placing the lettuce in cold storage. The field crates filled 
with lettuce are immersed for an hour or more in water having a 
temperature of about 3i° F. : the heads are then packed in the usual 
manner. The methods employed have added some expense to the 
cost of packing and packers have generally objected to handling the 
lettuce after it was taken from the cold water. Experience with 
thoroughly precooled lettuce indicates that such stock carries better 
and remains in good condition longer than lettuce that is not pre- 
cooled. 
At times, small quantities of lettuce are held in cold storage for 
limited periods after arrival in the markets. The length of time any 
particular lot may be stored and yet be withdrawn in good condition 
seems to depend primarily upon the condition of the lettuce at time 
of cutting, the promptness with which it is cooled to proper storage 
temperature, and the degree of care with which it is handled : but it 
rarely exceeds two weeks even under the most favorable conditions. 
Lots which will probably be held in storage for some time should be 
carefully selected. The heads should be bright, fresh, and crisp, not 
too mature, should contain no tipburn. decay, or other defects and 
should not be bruised or broken by careless, rough handling. The 
lettuce should be fairly dry ; when stored wet it slimes quickly. 
ORDERING CARS 
Whenever possible, requests for cars should be made at least 2J: 
hours before the shipper is ready to begin loading, in order to give 
the railroad agent time to make necessary provisions for the needed 
equipment. The car supply must always be taken into consideration 
by the shipper. In case of shortage the railroads frequently are 
unable to fill all orders for cars, and find it necessary to apportion 
the available supply among the shippers in accordance with their 
respective requirements. 
