1915] Casimir Funk 337 



disease that shows in every respect the greatest analogy i£ not 

 identity with rickets in children. One observes in these animals 

 every kind o£ deformation o£ various bones, chiefly the sternum, 

 deformities which may proceed so far that the intake o£ food is 

 rendered impossible. The mortaHty of these animals was very high, 

 sometimes as high as 80 percent. (I have observed several cases 

 of typical rickets in young growing rats which had been kept on 

 artificial diets.) I tried to diminish mortaHty in the chickens by 

 changing the food, by adding yeast, fresh grass and green vegetables, 

 but only with very sHght effect. It seems, therefore, that young 

 chickens can be raised without rickets only when they are kept in 

 the open air where they have opportunity to pick up worms. 



Two samples of cod-liver oil were at my disposal : a sHghtly 

 refined oil of brown color and a crude oil. By adding the two 

 kinds of oil to the ordinary diet a marked difference was observed, 

 the crude oil being very much more efficient in preventing the rickety 

 condition and diminishing the mortaHty of the chickens. Extrac- 

 tion of these two samples proved that the crude oil contained a much 

 higher proportion of nitrogenous extractives than the slightly puri- 

 fied oil. As my paper on this subject appears in this issue of the 

 BiocHEM. Bull. (p. 365), I shall refrain from mentioning here the 

 details of the work (108), except to say that the extraction products 

 will be tested clinically, as there is no reason to suppose, from our 

 present knowledge, that there is any particular value in the adminis- 

 tration of the oil as such. 



In studying the effects of these oils in infantile rickets, or even in 

 experimental rickets, we encounter great difficulties. In clinical 

 cases signs of rickets persist after the actual disturbance due to a de- 

 ficiency of vitamine has ceased. Marked effect of our preparation 

 could not be expected in such cases. Even in florid cases of rickets, 

 Observation had to be extended over long periods because effects 

 could not be expected to occur as promptly as they do after the 

 administration of beriberi- or scurvy-vitamine. 



In concluding this section I wish to express the belief that cur- 

 rent differences of opinion regarding the therapeutic action of cod- 

 liver oil are due to the use of highly refined oils by the clinicians. 



