It has been pointed out that Schaumann in 1908, sought to explain the etiology of beri-beri on the basis of specific starvation for some organic phosphorus compound. Further studies led him in 1912 to the isolation from rice polish-ings of a phosphorus-free base which was capable of curing experimental polyneuritis. This substance he called "activator," and assumed that its action was of an enzymic nature.

230. Funk's Designation Of The Anti-Beri-Beri Substance As "Vitamine."

Funk in 1912 (17) showed that a substance which was organic and of a basic nature could be isolated from rice bran by extraction with alcohol containing hydrochloric acid, which was precipitable by phosphotungstic acid, silver nitrate and barium hydroxid, and partially by mercuric chlorid. This caused the cure of polyneuritis induced in birds by feeding them polished rice. The following year he confirmed this observation and named the substance "vitamine" (18). In the same year Chamberlain and Vedder (20), and Edie, Evans, Moore, Simpson and Webster (21) confirmed these observations.

231. Suzuki's Designation Of The Anti-Beri-Beri Substance As "Oryzanin."

Almost simultaneously, Suzuki, Shimamura and Odaki (19) reported studies almost identical with those of Funk, and fully confirming the latter. They designated the substance which they isolated from rice bran, oryzanin. It thus became established that beri-beri, which is called polyneuritis when it is produced experimentally in animals, is due to starvation for a specific substance, of which but a surprisingly small amount is necessary to prevent the nervous symptoms characteristic of the disease.

232. Kohlbrugge's Conclusions Regarding The Cause Of Beri-Beri

Since the earlier experiments of Schaumann, there had been a tendency to associate beri-beri with scurvy and Barlow's disease. Kohlbrugge (22) associated the occurrence of these diseases with an unbalanced diet too rich in starch. He believed such a diet favored the growth of fermentative bacteria which formed sufficient acids to tend to self sterilization of the intestine, depressing or extinguishing the normal flora. He, therefore, designated them "fermentation diseases." These organisms were believed to occur in rice and other cereals, and were regarded as perhaps related to acetic acid formers. It was postulated that a diet containing free acids tended to hold the injurious kinds in abeyance. This view was opposed to that of Wright (23), who had in 1895 expressed the belief that scurvy was caused by the exclusive use of foods possessing a preponderance of acid elements over bases.

233. The Year 1912 Saw Great Developments In Our Understanding Of The Deficiency Diseases

It was in 1912, that the true relation of the diet to scurvy was brought to light. Hoist and Froelich (24) in that year discovered that a diet of cereals of different kinds or of bread caused the development of scurvy in guinea pigs, whereas a diet consisting of cabbage, carrots and dandelion did not cause the disease, although the animals lost 30 to 40 per cent in weight. The latter foods were found to be effective when administered to animals suffering from scurvy, in promptly relieving their symptoms. This, they found, could be done only with raw foods. Either cooked or dried cabbage, for example, was without virtue as an anti-scorbutic food. It seemed that in the course of cooking or drying something essential was destroyed.

234. The Discovery Of Vitamins Did Not Result In An Understanding Of Diet

Even after these discoveries had been made, however, no one was able to define in chemical terms what constituted an adequate diet. It was beginning to be appreciated that certain substances - vitamin - anti-scorbutic substance - must be taken into account in the planning of the diet in addition to the long recognized dietary essentials. Yet one, and probably two organic factors which are indispensable to normal nutrition in man, remained to be discovered, and future experimental studies were to reveal how surprisingly sensitive is the animal body to nice adjustments among certain of the inorganic elements. There still remained to learn how widely the proteins of various foods differed in their nutritive values, and there still remained to discover the exact dietary properties of each of the more important natural food-stuffs, which should make it possible to combine them in a manner suited to form a diet of optimal character.

235. There Are Two Forms Of Beri-Beri

It has been mentioned that beri-beri occurs in two forms, the wet and the dry. Those suffering from the dry type are usually at least somewhat emaciated, whereas those suffering from wet beri-beri are in a dropsical condition. Until very recently there was no clue to the cause of this difference. A brief history of the observations leading to its explanation will be of interest.