70 



SCIENCE 



[N. S. Vol. XLII. No. 1071 



and more stable than Nessler's reagent. It will 

 precipitate ammonia quantitatively and will give 

 accurate results nephelometrically. 



W. Denis: Phenols and Phenol Derivatives in 



Urine. 

 J. H. Long : On the Physiological Activity of Com- 

 bined Hydrochloric Acid. 



This paper discusses the behavior of betain 

 hydrochloride and glutaminio acid hydrochloride, 

 on the one hand, and certain protein compounds of 

 hydrochloric aeid, on the other, toward pepsin in 

 digestion. The hydrochlorides of amino acids, and 

 a number of similar bodies, are active in pro- 

 moting the peptic digestion of proteins in propor- 

 tion to the ease with which the aeid dissociates in 

 aqueous solution. In this respect the behavior of 

 betain hydrochloride is more marked than is that 

 of the glutaminic acid hydrochlorides or the hydro- 

 chlorides of other amino acids, although the aeid 

 appears to be active in all these bodies. 



The hydrochloric acid in combination with pro- 

 tein is much less readily dissociated, and there- 

 fore much less active. The amount of aeid which 

 may be combined with protein is not sufficient to 

 digest much more than the protein united with it. 

 For real digestion there must be some excess of 

 actual aeid, the hydrogen ion concentration of 

 which may be determined. The hydrogen concen- 

 tration of a number of mixtures of varying de- 

 grees of digestive activity is given. 

 J. H. liONG: On Combinations of Proteins with 



Halogen Acids. 



It has been long known that proteins and acids 

 combine in certain proportions, but all the condi- 

 tions of combination are not so clearly known. 

 The halogen acids and the halogens themselves 

 combine in very different ways. In this paper 

 combinations between casein, fibrin and egg albu- 

 min, on the one hand, and hydrochloric, hydro- 

 bromie and hydriodic acids, on the other, are dis- 

 cussed. It is shown that the rapidity of combina- 

 tion depends on several factors, as concentration 

 of aeid, temperature or agitation of the mixture 

 of protein and acid. Tables are given showing 

 variations with these factors. 



The amount of either acid which may be com- 

 bined with the proteins soon reaches a constant 

 maximum value by elevation of temperature, and 

 is relatively greatest with hydriodic aeid. But 

 because of the ready decomposition of this acid it 

 is diflficult to distinguish between the union Vfith 

 the acid and the substitution of the element itself. 

 The weights of the acids combined do not seem to 



be proportional to the molecular weights of the 

 acids. For each of the acids the amount which 

 may be held by a given protein decreases in the 

 order, egg, fibrin, casein. The reactions with 

 hydrochloric acid are very sharp, and with hydro- 

 bromie acid fairly so, but with hydriodic acid the 

 reducing action obscures the other to a marked 



Chas. Baskerville: On the Bate of Evaporation 

 of Ether from Oils and Its Application in Oil- 

 ether Colonic Anesthesia. 



The rate of evaporation of oil-ether mixtures 

 containing 25, 50 and 75 per cent, of the latter 

 was determined at body temperature. The oils 

 used were olive, peanut, corn, cottonseed, soya 

 bean, codliver and lanolin. 



The speed at which the ether evaporated from 

 the 75 per cent, mixture was found clinically to 

 be the best for introducing and maintaining anes- 

 thesia in the human by insertion in the colon. The 

 technique is indicated for operations about the 

 head, throat, mouth and the buccal cavity. 



Dr. Grwathmey, the senior collaborator, has rec- 

 ords of over a thousand cases with different opera- 

 tors without a single case of post-anesthesia pneu- 

 monia and with nausea reduced to the minimum. 



H. S. Gbindlet and E. C. Eckstein: The Free 

 Amid Nitrogen and the Free Amino-acid Ni- 

 trogen of Feedingstuffs. 



The free amid nitrogen of tankage, alfalfa hay, 

 and blood meal formed 0.84, 0.63 and 0.16 per 

 cent., respectively, of the total nitrogen of the 

 feedingstuff. 



The free amino-aeid nitrogen of tankage, alfalfa 

 hay, and blood meal formed 3.08, 2.87, and 0.36 

 per cent., respectively, of the total nitrogen of the 

 feedingstuff. 



The free amid nitrogen and the free amino-acid 

 nitrogen combined accounted for only one seventh 

 to one fourth of the total nitrogenous substances 

 present in the free amid and amino-acid extract of 

 these three feedingstuffs. 



H. S. Geindley, W. E. Joseph and M. E. Slater: 



The Quantitative Determination of the Amino- 



aoids of the Mixed Proteins of Feedingstuffs. 



The Van Slyke method has been applied to the 



quantitative estimation of the amino-aeids of the 



mixed proteins of feedingstuffs. While there are 



marked variations in the amino-aeid content of 



the mixed proteins of feedingstuffs expressed in 



per cent, of the total nitrogen of the feedingstuff, 



the variations are not as great, as a rule, as those 



for the individual proteins. The results show that 



