30 OUR HUMBLE HELPERS 



egg a covering as soft as thin parchment soaked in 

 water. " 



"Then soft eggs without any shell have this mem- 

 brane all exposed V 9 queried Jules. 



" Exactly. A new-laid egg has its shell completely 

 filled; but it soon loses some of its humidity, which 

 evaporates through the orifices in the shell. A void 

 is then created in the interior, near the large end, 

 where the evaporation is most rapid. At this end, 

 therefore, *the membrane detaches itself from the 

 shell that it lined and draws further in with the con- 

 tents of the egg shrunk by the evaporation. Thus is. 

 produced at the large end a cavity which the air from 

 outside enters and which for this reason is called the 

 air-chamber. This chamber, wanting at first, grows 

 little by little according to the space left by the mois- 

 ture's evaporation; consequently, the older the egg, 

 the larger the space. If the egg is placed under the 

 hen, the heat of the mother aids evaporation and 

 causes the quick formation of the air-chamber. 

 There gathers, as in a reservoir, the supply of air 

 needed for the vitality of the egg and the respiration 

 of the coming bird. So the empty space at the large 

 end is a respiratory storehouse. 



"When you eat an egg boiled in the shell, break it 

 carefully at the large end. If the egg is very fresh 

 the white will be seen immediately under the shell 

 without any empty space ; but if it is old you will find 

 an unoccupied hollow of varying size. That is the 

 air-chamber. According to its size you can judge of 

 the egg's freshness. But it would be more desirable 



