[Illustration: FIG. 14.--Failure of yeast as a prophylactic; latent scurvy promptly yielding to orange juice.] As is well known, yeast possesses the water-soluble vitamine in marked concentration. It is natural, therefore, that its antiscorbutic power was put to the test, especially as it has been accorded therapeutic value. Hess and Unger showed that autolyzed yeast was of no value in the cure of infantile scurvy (Fig. 14); Chick and Hume (1917) and Cohen and Mendel (1918) came to the same conclusion in regard to guinea-pig scurvy, making use of autolyzed yeast, yeast extract and dried brewers' yeast. In view of the fact that cod liver oil is practically a specific for human rickets, Hess and Unger tried the effect of this oil both in infantile scurvy and in that of guinea-pigs. It proved to have no protective or curative value. The animal experiments were confirmed by Cohen and Mendel. The use of olive oil also proved futile. Pitz in 1918 reported that in animal experiments he had found that lactose was able to protect against scurvy, and attributed this result to its power to alter the intestinal flora. We shall not enter into a detailed discussion of this question, as the study was carried out on a ration embodying unlimited and uncontrolled amounts of milk, and it has since been shown that the apparent cure was due to an increased consumption of milk by the animals in the progress of the experiment. Cohen and Mendel, Harden and Zilva, Hart, Steenbock and Smith (1919) all failed to protect or to cure their animals with lactose when they were placed on a ration which was definitely measured and limited. Hess and Unger failed to cure infantile scurvy by means of lactose. It has been suggested that scurvy is due to a lack of secretion of the endocrine glands, a question which will be referred to again in considering the relation of scurvy to other "deficiency diseases." With this idea Ingier added thyroid, hypophysis, thymus and parathyroid to the food of guinea-pigs, or gave it parenterally. She was unable to observe any beneficial results. Jackson and Moore met with the same result on feeding desiccated thyroid gland. We may add that we gave dried thyroid and also parathyroid glands in the treatment of infantile scurvy without effect. CONCLUSIONS