REPORT OF CRANBERRY SUBSTATION FOR 1916. 217 



ing the evaporation of moisture, as suggested in last year's report (pages 

 6 to 17). Cranberries, like other fruits, are living, breathing organisms 

 when picked, and must take in oxj^gen and give off carbon dioxide freely 

 to 'continue their Hfe processes. They may do this for several months 

 after they are taken from the vines. Lack of ventilation probably affects 

 them in much the same way that smothering does an animal, — by per- 

 mitting the accumulation of the carbon dioxide gas given oft' by their 

 tissues and thus reducing their supply of oxygen. The harmful effect 

 of the carbon dioxide appears to be prett}^ well demonstrated by the 

 experiments described by Dr. Shear and his associates in another part 

 of this bulletin (page 237). This gas appears to collect in injurious quan- 

 tities among cranberries, both in storage and shipment, because of the 

 closeness with which the fruit packs together and of the size of the con- 

 tainers used. 



As has been so splendidly demonstrated with apples,^ the rapidity of 

 the life processes in fruits varies directly with temperature, much more 

 carbon dioxide being given off at high than at low temperatures. While 

 cranberries may not behave exactly as apples do, it seems to follow that 

 low temperatures are important to cranberry keeping both in storage and 

 shipment, for with such temperatures the need of ventilation is probably 

 less. 



The general problem divides itself naturally into two parts, as follows : — 



(a) Storage previous to Shipment — Low temperatures, because of their 

 retarding effect on the process of respiration and on the growth of rot- 

 producing fungi, seem most important. The storage house, therefore, 

 probably should be constructed and managed to maintain such tempera- 

 tures, without resorting to artificial cold storage, at as little expense as 

 possible. This in turn, however, is likely in practice to depend largely on 

 arrangements for free but controllable ventilation. If, as the results of 

 the experiments described by Dr. Shear and his collaborators on page 238 

 seem to tend to show, a damp atmosphere does not injure the keeping of 

 this fruit, the thorough ventilating of the storage room during the night 

 and on cold days would be the cheapest means of obtaining low tempera- 

 tures, and they probably should be maintained as far as possible by the 

 use of dead-air spaces in the walls. To combine satisfactory arrangements 

 for free but controllable ventilation and for effective heat insulation at a 

 reasonable expense is probably, therefore, the main problem to be solved 

 by future builders of cranberry storage houses. Artificial cold storage for 

 cranberries has not been investigated much yet, and therefore is not con- 

 sidered here. 



(b) Preparation for Shipment. — While a low temperature is still prob- 

 ably desirable for cranberries after they leave the producer, this factor, 

 except as it may be utilized by cooling previous to shipment or by shipping 

 in refrigerator cars, is largely out of his control. He should, therefore, 



> F. W. Morse, Bui. No. 135, New Hampshire Agr. Expt. Sta., 1908, and Journal of the Ameri- 

 can Chemical Society, Vol. 30, No. 5, 1908. 



