11 March. 1918.] Importance of Butter Fat in Hu7nan Diet. 177 



aud fats, and nothing else is given to the animal, the animal will waste 

 away and die in a couple of months. 



Occurrence of Unknown. 



There is, however, another substance which was not appreciated until 

 1913, and that substance is always present in certain animal fats. I first 

 found it in butter-fat, but it is also present in the fat of eggs. It is 

 also present in the kidneys and liver, but it is not present in vegetables. 

 I want you to keep this second unknown substance in mind. The 

 dietarian who lives on vegetables alone does not get it in his food. 

 There is no shortage of it in nature, however, because while it is not 

 in vegetables, it would be obtained in the fats of milk and certain fats 

 of animal origin. There is an abundance of it in the leaves of plants. 

 Now, with two exceptions, the seeds of plants, so far as I know anything- 

 about them, are short of this one thing. 



Let me illustrate again the principle which I want you to keep in 

 mind. We will make 15 lbs. of a carefully purified mixture of protein. 

 We will take casein from milk, because it is easy to get and is an 

 excellent example; the grain starch, the sugars (of whatever origin you 

 want to get them) ; such fats as olive oil, lard, or whatever oil is readily 

 available; and any mixture of inorganic salts that is suitable — we will 

 put those together and feed the mixture to a young animal, and he will 

 waste away and die in a comparatively short time. It contains carbo- 

 hydrates and fats, and inorganic salts, but it is a total failure. 



]^ow, let us put in as part of the vegetable fat, say, 5 per cent, of 

 butter-fat, and feed it to an animal, and again he will die just as quickly 

 as if you didn't give him any food. Take this mixture of purified 

 foodstuffs, which contains a certain amount of butter-fats, and put it 

 with seeds and plants (except rice, and starch, and crystalline sugars), 

 and then add the leaf of corn or alfalfa ; it is a complete ration, and the 

 animal will thrive from infancy to old age. If you take 5 lbs. of purified 

 foodstuffs and apply to it this water soluble unknown, and leave out 

 the butter-fat, and leave in some vegetable fat, the animal is no better 

 off than if you had not left it in; but put in both these, and then your 

 feed becomes adequate, from infancy to old age. 



Butter-Fat Needed. 



We try another experiment with a pure protein, and we add a little 

 butter-fat to supply this unknown content, with a suitable salt addition, 

 and the animal will thrive from infancy to old age. It will have the 

 normal number of young, and they will rear their young. Now, if 

 you use neither of these and feed only oats and corn, he will die. If you 

 feed him on corn, he will die after a little while. And what is true of 

 one seed is, generally speaking, true of other seeds. Then if you mix 

 the two grains together, you will, in a certain measure improve the 

 mixture later. In other words, you have better protein if you mix two 

 seeds, and still better, probably, when you mix three. Now, when you 

 feed a mixture of oats, millet, and flaxseed, he will never grow one gram, 

 I do not care what species he is. To make this a good feed, you only 

 have to add two things. One of these is this water soluble, and the 

 other is common table salt. Such a mixture of seeds never contained 

 enough of that salt. You must put in u certain amount of lime content 



