The Preservation of Food in the Home. — Part II 1301 



2 Low temperature maintained by 



a Cold storage 



b Use of refrigerators 



c Ice houses 



d Cellars 



e Cold water 



3 High temperature: canned food 



4 Removal of moisture 



a Drying 



b Evaporating 



5 Use of preserving substances 



a Harmful 



(i) Borax and boracic acid 



(2) Salicylic acid and the salicylates 



(3) Benzoic acid and the benzoates 



(4) Formaldehyde 



(5) Sulfur and the sulfates 



(6) Copper 



b Harmless / 



(i) Sugar 



(2) Salt 



(3) Vinegar 



(4) Some spices 

 c Doubtful 



(i) Saltpeter 

 (2) Smoke 

 Full discussion of reasons for each of the methods named, their effective- 

 ness, and conditions indicating their use 

 Laws governing the use of preservatives and government reports concern- 

 ing the preservatives 

 Canned food 



1 Underlying principle of canning foods 



2 Methods of canning foods 



a By use of hot water bath 

 (i) On the stove 



Single process 

 Intermittent process 



(2) In the oven 



(3) In the fireless cooker, or a modification of it 

 b Stewing 



c Baking 



d The autoclave 



