60 EGGS IN COLD STORAGE. 



used for purifying- the rooms is itself first cooled and 

 purified, this man's idea is perfectly correct. 

 impurities ex- The free outside air during- warm weather, espe- 



isting-inthe . ... 



free outside air. cially in the vicinity of our large cities, contains, 

 among- many others, g-erms which produce the para- 

 sitic plant growth which is called mildew or mold. The 

 exhalation from the lung-s of the many animals and 

 men who inhabit our cities, and the evaporation 

 from the dust, dirt and decaying matter of various 

 kinds peculiar to the street, render the air a recep- 

 tacle and conveyor for impurities and germs of many 

 species. The species of germs which concern us are 

 active in proportion to the temperature and humidity 

 of the air. In a warm atmosphere which contains 

 much moisture they take root and grow rapidly, 

 throwing off more germs of their kind, which impreg- 

 nate the air in an increasing ratio as the humidity and 

 temperature are increased. The humidity of the 

 outside air is not necessarily increased with the tem- 

 perature, but it is always increased to some extent, 

 and as the temperature of the outside air rises we 

 must necessarily be more and more careful how we 

 treat and handle the air which we are to use for the 

 ventilation of refrigerator rooms. 



^ * s rea -^^y understood why it is necessary to cool 

 the air before introducing it into the storage room to 

 at least as low a temperature as that of the room to 

 be ventilated, and some cold storage managers have 

 ventilated on this basis, thinking that this was all 

 that was necessary for successful ventilation. Air 

 cooled only to the. temperature of the storage room 

 will be saturated with moisture at that temperature, 

 and will be in condition to develop mold rapidly. An 

 improvement on this manner of handling is to cool 

 the air to be used for ventilation to a few degrees (say 

 five or six) below the temperature of the storage 

 room. The air will then be rendered as dry as that of 

 the storage room. This is a good method of ventila- 



