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(ii. ) The very high temperatures realty necessary to destroy the seeds of germs, 

 as well as the germs themselves, can only be secured by apparatus not as yet 

 available for home use ; consequently, a false security may be enjoyed if 

 boiling only be accepted as sufficient protection to our food. 

 Protection of Water by Boiling. 



" What, then," you will ask, "about the protection of water by boiling?" In this 

 case the difficulty can be overcome to a great degree, because, in the first place, every 

 drop of water can be raised to boiling-point, given sufficient time. We know that the 

 germs of disease which are conveyed to us by water are killed if boiled for at least 

 half an hour. Therefore, where water is suspicious, the day's supply for drinking 

 purposes can be boiled for that length of time. 



"But how about the seeds of these germs," you will inquire; " should not they 

 also be destroyed?" This further protection can be extended to water by allowing it 

 to cool and stand for some hours and then boiling it for a second half-hour. In the 

 interval the seeds of any germs, if present, will develop into germs, in which form a 

 temperature of 212 Fahr. means death to them. 



It is believed that the germs of disease most often carried by milk namely, those 

 of tuberculosis are completely destroyed by a temperature rather below boiling-point ; 

 but, unfortunately, milk appears to suffer some change when cooked for the necessary 

 time, which renders it less wholesome for children. 



A Necessary Precaution for Soiled Milk and Water. 



Please note the importance of covering all water or milk which Aa,s- been boiled. 



It must be understood that the whole universe swarms with micro-organisms, some 

 of which are floating in the air, from which they fall upon our persons, our property, 

 and our food. Happily, most of these invisible millions are our good friends, and not 

 the least of their very valuable services is to protect our bodies and all forms of food 

 against the invasion of disease and putrefaction. 



(Fir, 5.) 



Food-preservation by means of a 

 layer of fat. 



Sometimes these benign and kindly germs are overpowered by the invaders. If 

 this occur in our bodies, we are sick ; if it occur in our food, decay sets in. Now, the 

 misfortune is that when milk or water is boiled, we kill our friends as well as our foes 

 among these germs. Therefore, if the undesirable germs, occasionally present in the 

 air, in dust, or in dirt, fall upon the surface of this defenceless milk or water, they can 

 carry on their mischievous activity unchecked. Sterilized food is defenceless food ; 

 therefore it must be sheltered by covering of a suitable kind. 



A slip of glass is to be preferred for this purpose. It fits closely to the rim of the 

 jug or bowl, arid shows every spot of dirt or greasy finger-mark. A cloth, however 

 clean it looks, may have been exposed to much dirt or handled by many grimy fingers 

 before it is used to cover a jug of boiled water or a bowl of boiled milk. 



Exposure to High Temperature. 



Exposure to a high temperature over a prolonged period alters in some way the 

 character of the food so treated. While protecting it in one direction, the heat seems 



