16 BULLETIN 471, U. S. DEPARTMENT OF AGRICULTURE. 



eggs. In the case of hard-boiled eggs the yolks are probably as digesti- 

 ble as those of less thoroughly cooked eggs. However, the whites are 

 so firm in texture that, unless they are finely chopped or thoroughly 

 masticated, the digestive juices will not be able to permeate them 

 quickly, and so portions may escape digestion or remain in the di- 

 gestive tract for several days and decompose. This explains why 

 hard-boiled eggs are often excluded from the diet of little children 

 and invalids and suggests that even healthy adults should be careful 

 to masticate them thoroughly. 



From all the evidence it seems fair to conclude that eggs are very 

 thoroughly digested and that the length of time of cooking has less 

 effect upon this factor than upon the time required for digestion in 

 the stomach. In a healthy man the latter consideration is probably 

 not a matter of much importance, as digestion will continue in the 

 intestine. In the diet of invalids it may be more important. How- 

 ever, diet in such cases is a matter for the attention of skilled physi- 

 cians, and one should be guided by their advice. 



Apparently there is no reason for believing that ordinary breakfast 

 beverages (tea, coffee, or cocoa) have any marked effect upon the 

 thoroughness of digestion of eggs, notwithstanding the popular 

 statement sometimes made to this effect. 



WHOLESOMENESS OF EGGS. 



Eggs are wholesome as well as useful and nutritious food. Over- 

 indulgence may lead to digestive disturbance, as it may with any 

 food, but, on the whole, eggs can be eaten by most people in usual 

 quantities without such results. Occasionally, however, a person is 

 found who is habitually made ill by eating eggs, just as there are 

 those who can not eat strawberries or other foods without distress. 

 Such cases are due to some personal idiosyncrasy, showing that in 

 reality " one man's meat is another man's poison." The physiologi- 

 cal explanation for them is probably that these persons have become 

 abnormally sensitized to a specific protein body in the egg which, will 

 then act as a poison when digested and taken into the circulation. 



Under certain conditions eggs, like other foods, may be accidental 

 carriers of disease by conveying to the body harmful bacteria or 

 parasites. It is possible for an egg to become infected with micro- 

 organisms, either before it is laid or more especially after it is 

 laid, since the porous shell offers no great resistance to microorgan- 

 isms, including those which cause it to spoil or rot. If an egg is eaten 

 raw or only slightly cooked, microorganisms, if present, can be com- 

 municated to man and may cause disease if they are of the sort to do 

 so. If an egg remains in a dirty nest, for example, defiled with the 

 microorganisms which cause typhoid fever, carried there on the hen's 

 feet or feathers, it is not strange if some of these bacteria occasionally 



