250 CARNEGIE INSTITUTION OF WASHINGTON. 



higher after food than before, and also higher in a relaxed position 

 than in an erect position. The conclusion drawn was that the 

 respiratory center was influenced by some factor in addition to the 

 hydrogen-ion concentration of the arterial blood. 



THE DETERMINATION OF ACETONE AND i3-0XYBUTYRIC ACID IN URINE. 



The importance of the accurate and rapid determination of ace- 

 tone and /3-oxybutyric acid in a study of acidosis, and particularly 

 diabetes, led to an attempt to better the existing methods. By 

 modifying the condensing and the oxidation, the time required for 

 the distillation of the acetone was materially shortened and control 

 tests indicated a considerable increase in accuracy. It was esti- 

 mated that the acetone and /3-oxybutyric acid can be determined 

 by this modified method in about one-third of the time formerly 

 required, the apparatus being relatively simple and easily developed. 



MINERAL CONSTITUENTS OF THE URINE OF A FASTING MAN. 



Based upon his experience in the laboratory of Dr. Francis H. 

 McCrudden, of the Rockefeller Institute for Medical Research, Mr. 

 Bock has made complete analyses of the mineral constituents of the 

 urine of the fasting man. Similar determinations of the mineral 

 constituents of feces passed after concluding the fasting experiment 

 contribute to the research as a whole. 



VAPORIZATION CALORIMETER. 



The principle of the large respiration calorimeter in this laboratory, 

 ^. e., that of absorbing the heat given off by the man by a current of 

 cold water flowing through suitable absorption pipes, is admirably 

 adapted for measuring large quantities of heat. Since it seemed 

 probable that another principle, which would do away with tem- 

 perature measurements and secure continuous records, would be 

 much more advantageous for measuring the small amount of heat 

 given off by infants or by small animals, a research has been begun 

 on the development of a calorimeter based upon the measurement 

 of the amount of ethyl alcohol vaporized at extremely low pressure. 

 Excellent progress has been made, although the calorimeter has not 

 yet been fully developed. 



PSYCHOLOGICAL OBSERVATIONS IN CONNECTION WITH EXPERIMENTALLY 

 INDUCED ACIDOSIS. 



One of the first problems undertaken by Professor Dodge, in the 

 division of physiological psychology, has been the study of the in- 

 fluence of an experimentally induced acidosis upon the reaction time 

 and the simpler reflexes. This was carried out in connection with the 

 acidosis experiments made in the laboratory at the end of 1912, when 

 the technique, method of handling the subject, and the order of tests 

 were carefully studied, resulting in improved plans for further work. 



