670 EXPEEIMENT STATION RECORD. 



have to do with the effect of diet on the excretion of potassium. According to 

 the author, the excretion is greater oji a diet rich in protein and poor in car- 

 bohydrates than on one in which these conditions are reversed. 



The relation between potassium excretion and sodium is also considered. See 

 also a previous note (E, S. R., 25, p. 67). 



A critical study of the process of acid excretion, L. J. Henderson {Jour. 

 Biol. Chcm., 9 {1911), No. 5, pp. Jf03-Ji24, dgim. 3). — As is the case with tem- 

 perature and osmotic pressure, normal neutrality or alkalinity, the author 

 concludes, is adjusted by a mechanism within the body, but is maintained 

 permanently by exchanges with the environment. 



"The acid end products of metabolism, without appreciably changing the 

 actual alkaline reaction constantly take up alkali from blood and protoplasm. 

 In this manner there is a tendency to disturb the normal protective equilibrium 

 between bases and acids. This tendency is held in check by the kidney, which 

 In the process of urine formation reverses the reaction of neutralization of 

 acid and restores to the blood that alkali which has served as a carrier of acid. 



"The process may be measured both quantitatively and in respect to its 

 efficiency. The quantity of acid excreted is measured by the amount of alkali 

 which must be added to urine in order to obtain the reaction of blood plus 

 the amount of urinary ammonia." 



A method for carrying out such measurements is described. 



According to the author's investigations " the preservation of the normal 

 alkalinity of the body is due, in important measure, to but two independent 

 factors, excretion of ammonia and excretion of phosphates. The elaboration 

 of ammonia and the presence of phosphoric acid as an end product of meta- 

 bolism make possible the excretion of acid ; regulation of ammonia production 

 and of the ratio of the acid to the alkaline phosphates of urine are the means 

 of regulating the acid excretion." 



The pressor bases of the urine — the effect of age, diet, and high blood 

 pressure on their excretion, W. Bain {Lancet [London], 1911, I, No. 21, pp. 

 1409-1411, figs. 3). — Pressor bases — that is, substances which raise the arterial 

 blood pressure of animals when injected intravenously — are absent from the 

 urine of children from 10 to 12 years of age and apparently begin to be excreted 

 at about the age of 14. 



"A vegetable diet considerably reduces the amount formed. Eggs and fish 

 reduce the quantity to some extent, but if chicken is taken the amount is but 

 little less than one obtains on an ordinary mixed diet containing butcher's meat. 



" The bases are either absent or considerably diminished in cases of high 

 blood pressure. Doubtless the diminution in some cases is partially attributable 

 to low dietary, but in most of the cases recorded in this paper the only possible 

 explanation is that the bases are retained in the system and produce the rise in 

 pressure. 



" In gouty patients with normal blood pressure the pressor bases are excreted 

 in normal amounts." 



Methods of studying- diet in different classes of society, P. Albertoni and 

 P. TuLLio (2. Cong. Internat. Hyg. Aliment., Bntxelles [Proc], 1 {1910), Sect. 



1, pp. 130-168). — ^Methods for conducting dietary studies and related work are 

 outlined and results of the investigation of Albertoni and Rossi summarized 

 (E. S. R., 25, p. 266). 



The energy value of food materials and dietary standards, H. Kcettlitz 



2. Cong. Internat. Hyg. Aliment., Bruxelles [Proc], 1 {1910), Sect. 1, pp. 

 23-33). — From a summary of data the author concludes that the conflicting 

 results obtained by the various investigators indicate clearly that nutritive 

 requirements vary with individuals and with the same individual under differ- 



