THE ICE CHEST 151 



moisture which condenses upon the surface of the cold 

 fruit when it is placed in warm or damp air. Such sur- 

 face moisture, as we have seen, furnishes the necessary 

 condition for the starting of mold growth. The prac- 

 tical lesson to be learned is that after the material has 

 been removed from the cold storage and warmed up to 

 ordinary room temperatures it should be consumed as 

 rapidly as possible, because putrefaction and decay are 

 sure to take place speedily. If not used at once, it must 

 be kept in an ice chest. There is practically as much 

 difficulty in keeping food bought in the markets from 

 decay in the winter, if kept in a warm house, as there 

 is in the summer. 



Cold-storage plants are hardly found outside of large 

 cities, and persons at a distance must depend upon other 

 means of producing low temperatures. These are easy 

 to obtain in winter, but difficult in summer. 



2. Temperature of an Ice Chest. A far less efficient 

 means of obtaining low temperature is by the use of the 

 ordinary ice chest, less efficient than cold storage simply 

 because the temperature is higher. The temperature of 

 ice chests is variable, depending upon the size of the chest 

 and the amount of ice in it. It will sometimes be as low 

 as 40, or even lower, but never quite reaches the freezing 

 point ; at other times it will run up to 50, and as the ice 

 melts the temperature rises to that of the outer air. Food 

 preserved in an ice chest is far less thoroughly protected 

 than in cold-storage plants. The use of the ice chest is 

 simply a means of checking the development of bacteria, 

 but it by no means stops their growth. At the tem- 

 perature of 40 most bacteria, if they grow at all, grow 



