No. I, November, 1921] PHYSIOLOGY 47 



the dialysis of tissue with little loss of enzyme. This effect is ascribed to adsorption, following 

 a change in the reaction of the proteins to which the enzyme had been bound. The use of 

 dipotassium citrate as a buffer in determining the peroxidase value retarded the formation 

 of purpurogallin. A raw preparation was made by coarse maceration, dialysis for 8 days, 

 treatment with oxalic acid, the addition of barium hydroxide in alcohol, neutralizing with 

 carbon dioxide, and centrifuging. In the solution, bichloride of mercury precipitated a basic 

 glucoside and freed peroxidase; this enzyme is amphoteric. It is adsorbed by a variety of 

 agents, aluminium hydroxide being best. A limited ratio of this substance adsorbed 80 per 

 cent of peroxidase in h hour from a 0.05 per cent solution of enzyme in dilute alcohol. Carbon 

 dioxide favors elution (diffusion of enzyme from adsorption medium to solvent), the process 

 having little temperature effect, and reaching an equilibrium in about 1 hour. Protocols 

 show the method of adsorption of enzyme to be much superior to that of adsorption of impuri- 

 ties. By the best method evolved, 5 kgr. of roots (presumably horseradish) gave a yield of 

 0.31 gr. of the enzyme preparation with a purpurogallin number of 860. — W. E. Tottingham. 



METABOLISM (RESPIRATION) 



286. Bailet, C. H. The storage of wheat. Operative Miller 24: 352, 381-382. Fig. 

 1-4. 1919;25:5-6. Fig. 5-7. 1920. — Heating of grain in storage is caused by respiration, 

 which experiments indicate to be about 20 times as great in the embryo as in the endosperm. 

 Determination of the CO2 produced by lots of plump, hard spring wheat stored at 100 F. for 

 4 da}^s at known varying moisture contents, showed a steady increase in heat as the moisture 

 was increased from 12 to 14.5 per cent, and a very rapid rise thereafter. Twice as much heat 

 developed at 15 per cent as at 12.5 per cent, while more than 5 times as much developed at 

 16 per cent. At a moisture content of 13 per cent there was little difference between hard 

 spring and soft wheats in the amount of heat produced, but at a moisture content of 13.6-13.8 

 per cent the soft wheats produced as much heat as hard spring wheat at 14 .5 per cent. Shrunk- 

 en wheat, having a bushel weight of 47.5 pounds, produced as much heat at 12.8 per cent 

 moisture content as did plump hard spring wheat at 14.5 per cent. The weight per kernel of 

 the shrunken wheat was less than half that of the normal wheat so that the proportion of 

 embryo was much larger. Frosted wheat kernels also respired much more rapidly than sound 

 wheat, due in part to the greater sugar content. — The respiration of wheat increased with 

 increase in the period of damp storage. Wheat stored at room temperature respired more 

 vigorously than wheat stored at a temperature slightly above freezing. Respiration increased 

 steadily with rise of temperature from 35°C. up to 55°C., after which it steadily diminished. 

 Respiration diminished as the quantity of accumulated CO2 increased. — Carleton R. Ball. 



287. Brooks, Matilda M. Comparative studies on respiration. XIV. Antagonistic action 

 of lanthanum as related to respiration. Jour. Gen. Physiol. 3 : 337-342. 1921.— Concentrations 

 of La(N03)3 weaker than 0.0000025M have little effect on the respiration of Bacillus subtilis 

 as measured by the production of COa according to the Osterhout method. At 0.000006M 

 there is an increase in the rate while at concentrations above 0.000025M there is increasing 

 retardation. Distinct antagonistic effects between La(N03)3 and NaCl are evident from 

 respiration measurements while only slight antagonism is evident between La(N03)3 and 

 C&CU.— Otis F. Curtis. 



288. Brooks, Matilda M. Comparative studies on respiration. XV. The effect of bile 

 salts and of saponin upon respiration. Jour. Gen. Physiol 3: 527-532. 1921.— The addition 

 of sodium taurocholate produces an increase in the rate of respiration of Bacillus subtilis at 

 a concentration of about 0.0000125M and decreases the rate at higher concentrations. Antag- 

 onism was found between NaCl and sodium taurocholate as measured by respiration. Solu- 

 tions of saponin at concentrations between 0.00005M and O.OOIM retarded respiration while 

 at lower concentrations no effect was noticeable. — Otis F. Curtis. 



289. GusTAFSON, F. G. Comparative studies on respiration. XII. A comparison of the 

 production of carbon dioxide by Penicillium and by a solution of dextrose and hydrogen peroxide. 



