Rural School Leaflet 



1 167 



a fresh one. Compare the appearance of the eggs examined with that 

 of eggs in the different stages of evaporation shown in the figure on the 

 opposite page. Fresh eggs often contain clots of blood or other sub- 

 stances, which appear as dark spots floating in the egg. Such eggs may 



Rate of evaporation of hens' eggs, hetd at ordinary room temperature. The rate of evapora- 

 tion could be greatly lessened by keeping the egf^s cooler a nd by having more moisture in the air 



1, A newly laid egg. When an egg is just laid and not yet cooled, it has no air cell at all. 

 While it is cooling, however, the contents contract, and an air cell of the size shown here 

 is formed. The air cell is usually at the large end of the egg 



2, An egg one week old. The size of the air cell continually increases, due to evaporation 



of the moisture 

 J, An egg ttvo iveeks old. 



4, An egg three weeks old. 



5, An egg four weeks old. 



6, An egg five weeks old. 



7, An egg six weeks old 

 S, An egg seven weeks old 



Such eggs are not of first quality 

 By this time the ivhite of the egg begins to iveaken 

 The yolk appears as a darker shadow than before 



Eggs evaporated as badly as this should not be sold 



often be used at home, but should not be sold with the regular market 

 eggs. The best success will be obtained by selling only eggs that are 

 strictly fresh as determined by candling. 



Editors' note. — No part of the poultry business is more important than 

 the marketing 01 the product. In order to be most successful and to sell 

 at the best price, one must establish a reputation for quality and never 

 depart from it. The article on "Candling Market Eggs " and the one on 

 "Grading and Packing Eggs" emphasize this thought. The candling 

 device makes it inexcusable for a poultry raiser to sell a poor egg along 

 with good ones, and he should always sell a product that is guaranteed to 

 be what it is marked to be. 



