FOODS ANB FOOD HABITS 45 



Some Characteristics of Fats. Some fats, e. g. butter, 

 are very pleasant to taste, while others, like castor oil, are 

 decidedly unpleasant; some are easily swallowed, while others 

 can be swallowed only with difficulty. The reason for this 

 is that three different kinds of fatty materials are mixed 

 together in the ordinary fats of our foods; one of these, 

 called olein, melts at 23 F. (-5 C.); a second, palmatin, melts 

 at 113 F. (45 C.); and a third, stearin, melts at 140 F. 

 (60 C.) It is easy to see that the more olein a fat contains 

 the more easily it can be melted. Olive oil is mostly olein 

 and is melted at ordinary temperatures, while beef tallow 

 contains much stearin and is solid even at the ordinary 

 temperature of the body. Butter and lard are quite soft 

 because they contain a large proportion of the easily melted 

 olein. It is well to remember also, that the easily melted fats 

 are the most readily digested. 



Fats constitute an extremely important part of our food 

 since they are so easily digested and yield so much energy. 

 All fats, whatever their special natures or flavors, serve much 

 the same purpose. 



Vitamines. Until very recently it has been believed that 

 the three food materials above discussed, together with salts 

 and water, were all that is necessary for an ample diet, and 

 that new protoplasm is readily made from them alone. Cer- 

 tain diseases, e.g., a form of neuritis ("beri-beri"), an intestinal 

 disorder (scurvy), and rickets, were explained as due to the 

 use of incorrect proportions of the foods already mentioned. 



It is now clearly proven that substances called vitamines 

 must also be eaten and when used, the illnesses referred to do 

 not occur, or if present, are cured. 



Vitamines are found in the seed coats of most cereal grains, 

 in yeast, in whole milk and butter, in eggs, in leafy vegetables 

 (especially spinach), and in the juices of commonly eaten 

 fruits, e. g., oranges, apples, etc. These substances are 

 destroyed in boiled milk, and as fruits are heated when canned , 



