F. W. TANNER 507 



tables, while appearing elucidative, leave something to be desired. In many of the 

 cases the time of the yeast treatment is not given nor is the reader informed of the 

 length of the period of the cure or whether the symptoms appeared again when the 

 yeast treatment was stopped. 



Murlin and Mattill' carried out an extensive study of the laxative action of yeast 

 in which were used both human and animal subjects. They observed a laxative 

 effect in most cases when three cakes a day were eaten. However, they could not 

 confirm the statement of Hawk and his colleagues that killed yeast was as active as 

 living yeast. Intestinal putrefaction was also somewhat diminished. It is interesting 

 to note, also, that as soon as the yeast treatment was stopped, the subjects came back 

 to normal. The subjects of these experiments were young men "some of whom suf- 

 fered from constipation." 



Heintz and Welker,- in using yeast ingestion for certain pathologic conditions, 

 were interested to learn the mechanism of the action of yeast. They used twenty-two 

 young medical students and reported that the ingestion of three cakes of yeast daily 

 caused a marked increase in the leukocyte count. Ten subjects were chosen for estab- 

 lishing a "base line" for comparison with the subjects who were given the yeast. Six 

 of these showed a small variation from day to day, three of the remaining developed 

 respiratory infections, and the remaining one showed a decided rise in the leukocyte 

 count without any apparent reason. This last man was dropped from consideration. 

 Were the authors certain, then, that none of the men to whom yeast was fed did not 

 show the same increase, this increase being attributed to the yeast? Heintz and 

 Welker stated that no infections were observed among the men on the yeast treat- 

 ment. If the one control subject who was dropped out because his leukocyte count 

 increased for no apparent reason had been left among the controls, of whom six were 

 used, the conclusions appended to the paper would have been considerably modified. 

 Wolf and Lewis-' found that eating yeast had no stimulating effect on the production 

 of antibodies. Antibody production was even lower in the controls. 



The next question that may be considered is what happens to the yeast in the 

 intestines. This was studied by Rettger and his colleagues.-' Bakers' yeast was found 

 to undergo a rapid destruction in the alimentary tract. Less than i per cent of the 

 cells appeared alive in the feces. When yeast-feeding stopped, both the dead and 

 living cells disappeared from the alimentary tract. After three days relatively few, 

 if any, living cells remained. No effect on the relative proportion of gram negative 

 and gram positive bacteria was demonstrable, from which we might infer that there 

 was little antagonistic action, if any, between the yeast and intestinal bacteria. 



Davison^ fed one-quarter to one-half of a yeast cake per day to nine infants for 

 periods of eight to twenty-three days. Such a procedure was reported to be not only 

 without benefit but definitely harmful in some cases. Abdominal distention occurred 

 in some of these infants, and their stools became more frequent. The general tone of 



' Murlin, J. R., and Mattill, H. A.: Am. J. Physiol., 64, 75. 1923. 



^ Heintz, E. L., and Welker, W. H.: Arch. Int. Med., 35, 500. 1925. 



3 Wolf, E. P., and Lewis, J. H.: /. Infecl. Dis., 25, 311-14. 1919. 



'' Rettger, L. F., Reddish, G. F., and McAlpine, J. G.: /. Bad., 9, 327. 1924. 



s Davison, W. C: Am. J. Dis. Child., 24, 339. 1922. 



