No. 2, March, 1921] PHYSIOLOGY 199 



series, with and without 1 per cent glucose. NH4N0:i, Ca(NO;02, and (NH^)2S04 were also 

 used in the presence of inannite. At the end of from 5 to 7 months the cultures were analyzed 

 for total nitrogen, the Gunning-Kjeldahl method being used for media free from nitrates, and 

 the Forster modification where niti'ates were present. In the urea, glycocoU, asparagine and 

 (NH4)2S04 series no marked increase or decrease occurred either in the presence or absence of 

 glucose or mannite. Marked increases were found in NH^NOs and Ca(N03)2 media in the 

 presence of glucose, the amount of fixation ranging from 6 to 10 mgm. per culture in the 1917- 

 1918 experiments and from 4 to 13 mgm. in the 1919 experiments. This represented an increase 

 in total nitrogen ranging from 17 to 55 per cent. Fixation was common to all spec'es. The 

 amount of fixation varied somewhat with the different species and seemed to be related to the 

 intensity of growth. — A. H. Chivers. 



1336. Warburg, Otto. Uber die Reduktion der Salpetersaure in griinen Zellen. [The 

 reduction of nitric acid in green cells.] Naturwissenschaften 8:594-596. 1920. — Little is 

 known of the conditions of reduction in higher plants as it is usually covered up by the oxi- 

 dation processes. Warburg has succeeded, however, in increasing the rate of reduction to 

 such an extent that the chemical nature of the process can be studied. He used in his experi- 

 ments the alga Chlorella vulgaris Beyerinck and by growing it in dilute solutions of nitric acid 

 was able to stimulate the reduction of nitrates to such an extent that in darkness the reduc- 

 tion made up 55 per cent of the entire metabolism, and in light a much greater part, without 

 injurious effect on the alga. — Orton L. Clark. 



METABOLISM (ENZYMES, FERMENTATION) 



1337. Colin, H. L'inulase duTopinambour. [The inulase in Jerusalem artichoke.] Rev. 

 Gen. Bot. 32:247-255. 1920. — The author finds that the tubercles of Jerusalem artichoke 

 are not an exceptionally good source of inulase. Colin finds that "helianthenine" is not a 

 stage in the breaking down of inulin, and in this he disagrees with Green. ^J. .1/. Brannon. 



1338. Colin, H. Sur I'inversion diastasique du saccharose; influence des produits de la 

 reaction sur la Vitesse d'hydrolyse. [On the diastatic inversion of saccharose: the influence 

 of the products of the reaction on the rate of hydrolysis.] Compt. Rend. Acad. Sci. Paris 169: 

 849-852. 1919.— The author has previously shown that diminution of the rate of reaction of 

 invertase with increase in the amount of saccharose present is to be imputed to increased vis- 

 cosity of the solution and that the rate of reaction is a linear function of the fluidity of the 

 solution. In order to determine the specific effect of the end products of the inversion of sac- 

 charose on the rate of inversion, invert sugar, levulose, and glucose were added to mixtures 

 of saccharose and invertase and their effect on the rate of reaction was noted. It is concluded 

 that the rate of hydrolysis of saccharose is primarily a fvmction of the fluidity of the solutions, 

 and the retarding effect of glucose, levulose, and invert sugar on this rate is attributed to the 

 augmentation of the viscosity of the medium. The products of the reaction exert no other 

 effect on the rate of inversion than would some other neutral substance, glycerine for example, 

 which increased the viscosity of the liquid in a similar fashion. — V. H. Young. 



1339. Flohil, J. T. Volumetric method for the determination of diastatic capacity. Jour. 

 Indust. Eng. Chem. 12: 677. 1920. 



1340. Gore, H. C. Occurrence of diastase in the sweet potato in relation to the prepara- 

 tion of sweet potato syrup. Jour. Biol. Chem. 44: 19-20. 1920. — Sweet potatoes are high in 

 diastatic power, and it is possible to convert nearly all of their starch into soluble carbohy- 

 drates by slowly cooking the potatoes in water. — G. B. Rigg. 



1341. KoPELOFF, N. Effect of varying the amount of inoculiun and concentration on the 

 deterioration of sugar by molds. Jour. Indust. Eng. Chem. 12: 455-457. 1920. — An increase 

 in the number of mold spores inoculated into sugars (with films of varying concentration) is 

 responsible for an increase in deterioration. The amount of deterioration also increases with 

 a decrease in concentration of the films surrounding the sugar crystals. — Henry Schmitz. 



