284 THE CHEMISTRY OF GROWTH AND REPAIR 



thereof. From rice polishings has been obtained a crystaUine sub- 

 stance, of which a dose of 20 to 30 milHgrams will cure a polyneuritic 

 bird. As stated above, the pure active substance has not been 

 isolated and its exact nature is undetermined. Vedder believes that 

 it is something that is needed for the repair of nervous tissue, so that 

 in its absence the nervous tissues degenerate. The paralysis, he 

 believes, depends more on central than peripheral- nerve changes, 

 since the degeneration of the nerves precedes the paralj^sis and maj^ 

 persist long after the paralysis has disappeared. As rice polishings 

 relieve the cardiac symptoms, which are important features of beri- 

 beri, it is to be assumed that the vitamine is essential for the heart 

 metabolism. Furthermore, heart muscle contains vitamine which 

 will protect from polyneuritis birds fed on polished rice. This does 

 not seem to be identical with the vitamine isolated by Funk, for 

 while it relieves the cardiac symptoms and dispels the dropsy of wet 

 beriberi, it does not cure the paralytic symptoms of dry beriberi, 

 according to Vedder. This author "has a growing belief that dry 

 and wet beriberi are separate and distinct diseases, which are, how- 

 ever, generally associated." Rice polishings, he says, clear up beri- 

 beri dropsy quickly, but do not affect the paralysis unless the 

 polishings have been hydrolyzed. 



Walshe^^ calls attention to the fact that starved fowls live long 

 enough to develop beriberi, yet nevertheless do not show it, so he 

 thinks that there must not only be a deficiency factor, but also some 

 positive factor, which may be the abundant carbohydrate of the 

 rice diet. Possibly in the absence of the vitamine the carbohydrate 

 metabolism is altered, with the production of toxic substances. 

 Furthermore, in spite of the marked clinical results obtained with 

 rice polishings, the disease is not always cleared up as readily as 

 might be expected if only a lack of vitamines was concerned, and, 

 therefore,, there still remains the possibility that some infectious 

 factor may play at least a subsidiary part in human beri-beri (see 

 Mitchell 3^''). 



Keratomalacia or Xerophthalmia,'^ a condition of opacity of 

 the cornea, followed by ulceration and blindness, seems to be specifi- 

 cally due to lack of the fat-soluble vitamine which is present in egg 

 yolk, butter fats, green leaves, etc., but not in lard or in many vege- 

 table oils. This disease can be produced readily in experimental 

 animals by feeding diets free from proper fats, and is relieved by 

 administration of small quantities of these fats. I have had the 

 opportunity to observe numerous instances of xerophthalmia among 

 the famine sufferers in Roumania, and to observe its prompt relief 

 under cod liver oil feeding. It should not ha confused with simple 



" (iuart. Jour. Med., 1918 (11), 320. 



^8 Bloch, Ugeskr. f. Laeger., 1918 (80), 815. 



