260 EXPERIMENT STATION RECORD. 



in diet. In the other institution there was a recurrence in the case of only one 

 of the 105 pellagrins and no new case in the G9 nonpellagrin residents. 



Since a similar modification of the diet in certain wards of the Georgia State 

 Sanitarium no evidence of recurrence in any of the pellagrins has been ob- 

 served, although 47 per cent of the control pellagrins in wards where the diet 

 had not been modified showed a recurrence. 



" The conclusion is drawn that pellagra may be prevented by an appropriate 

 diet without any alteration in the environment, hygienic or sanitary." 



As a practical application of this experimental data, the author recommends 

 the following modifications in the diet of a population where pellagra is espe- 

 cially prevalent: An increase in the amount of fresh animal and leguminous 

 foods, especially during the late winter and spring, and a reduction in the diet 

 of carbohydrate foods. 



A bibliography is appended. 



Changes in the hydrog'en ion concentration of the blood produced by pul- 

 monary ventilation, T. H. Milkoy {Quart. Jour. Expt. Physiol., 8 (1914), No. 

 2-3, pp. 141-153). — Pulmonary ventilation experiments were conducted with air, 

 air and oxygen, and gas mixtures rich in carbon dioxid for the purpose of de- 

 termining the effect of these factors on the hydrogen ion concentration of the 

 blood. Analyses were made of the blood of cats and dogs as the experimental 

 animals. Among other conclusions, the author suggests that, due to the short 

 duration of the variations of hydrogen ion concentration in the blood, this factor 

 is closely related to the activity of the respirati^-y center. 



A comparison of methods for determining the respiratory exchange of 

 man, T. M. Cakpenteb (Carnegie Inst. Washington Pub. 216 (1915), pp. 265, 

 figs. 72, pi. 1). — This publication reports in great detail an extensive study of 

 the comparative value of several different methods of measuring the respira- 

 tory exchange in man. The forms of apparatus used in the investigation were 

 the bed respiration calorimeter, the two types of the Benedict universal respi- 

 ration apparatus, the Zuntz-Geppert apparatus, the Tissot method, the Douglas 

 method, the Mueller valves, two forms of the Haldane gas-analysis apparatus, 

 and a small hand spirometer. A detailed descrii>tion of each of these types 

 and the method of using them comprises the first part of the publication. 



The results of the tests are reported in detail. Normal, healthy young men 

 were used as subjects; during the experiments they usually were placed In a 

 reclining position. The comparisons of two forms of apparatus were made 

 under the same conditions and on the same day. Determinations were made of 

 the elimination of carbon dioxid, the consumption of oxygen, the pulse rate, 

 and the respiration rate. The muscular activity of the subject was also re- 

 corded. In some experiments a determination was made of the volume of 

 respiration and the total ventilation of the lungs. 



The third part of the publication is devoted to an extended critical discussion 

 of the different types of respiration apparatus and their technique. Especial 

 consideration is given to the sources of error and to the relative advantages 

 and disadvantages of each method. In concluding the report, several ixiges are 

 devoted to a discussion of a number of factors influencing the accuracy of the 

 results obtained in these and other experiments on the respiratory exchange of 

 man. 



For the details of the discussion and of the experimental data the original 

 publication should be consulted. 



Energy transformations during horizontal walking. F. G. Benedict and H. 

 MuRSCHAFSER (Camcgie Inst. Washington Piih. 231 (1915). pp. 100. figs. 6. 

 pi. 1). — Tlie object of this investigation was to study the increase in metabolism 

 due to walking on a level at increasing rates of speed. An extensive review is 



