612 



SCIENCE 



[N. S. Vol. LII. No. 1356 



Temperatures vary quite badly from the 

 normals. One year differs from another by 

 about .5° F. One January differs from an- 

 other by about 2° F. and one January 4 from 

 the January 4 of another year by an average 

 of 4° F. These departures are caused mainly 

 by the passage of storms with their alternate 

 warming or cooling effects. In the arid west 

 where irrigation and dry-farming are prac- 

 tised (one fourth of the earth's land area is 

 equally dry) 80 per cent, of the days are free 

 from rain, the sky is clear most of the time 

 and the humidity is only 50 per cent. The 

 departures from normal are, therefore, slight. 

 Equation ISTo. 2 will therefore give actual 

 temperatures aproximately for this large area. 



These actual hourly temperatures differ 

 from the normals by from 0° F. to occasionally 

 as much as 15 or 20° F. The normal calcu- 

 lated from equation two differs from the 

 actual temperatures in the arid west by 5° F. 

 It should be remembered, however, that the 

 same equations gave the normal temperatures 

 correct to 2^° F. 



The TJ. S. Weather Bureau has continuous 

 temperature records for several hundred cities 

 for several decades and daily maximum and 

 minimum temperature records for several 

 thousand more cities. The equation sub- 

 mitted states approximately the law of this 

 change in temperature with the time. Its 

 simplicity and its generality are striking. 



It has practical value in such cases as the 

 determination of early morning temperatures 

 where heating to protect crops from frost is 

 practised, in calculating hourly values where 

 thermograph records have not been taken and 

 for engineers engaged in laying concrete, in 

 determining the normal time in the spring 

 and fall when freezing temperatures are ex- 

 perienced during working hours. 



Frank L. "West 

 Utah AGRicuiiTURAL Experiment Station 



THE AMERICAN CHEMICAL SOCIETY 



(Continiied) 

 The dynamics of the catalase reaction: Seegius 

 MoRGULis and Victoe E. Levine. Many of the 



recent investigations on catalase are of little 

 value because of incorrect technique and lack of 

 appreciation of the dynamics involved. To draw 

 proper deductions from experimental data it is 

 necessary to select the proper method for the 

 preparation of the enzyme and the proper preserv- 

 ative, and to regulate the hydrogen ion concen- 

 tration of the enzyme as well as of the substrate. 

 The shaking must be uniform and must begin al- 

 most as soon as the substrate comes in contact 

 with the enzyme. The determination of the rate 

 of evolution of oxygen is of greater importance 

 than that of the amount of oxygen yielded within 

 a given time. A ratio between the enzyme and 

 substrate must be established such that the amount 

 of oxygen liberated is directly proportional to the 

 catalase concentration. For every catalase con- 

 centration there is an optimum amount of hydro- 

 gen peroxide. Increasing the peroxide beyond 

 this amount results in a considerable progressive 

 showing up of the reaction. The decomposition 

 of hydrogen peroxide is a monomolecular reaction 

 under the conditions of a constant substrate: 

 enzyme ratio. With a constant quantity of enzyme 

 the relation between hydrogen peroxide and the 

 reaction velocity becomes inverse and logarithmic 

 as soon as the concentration of hydrogen peroxide 

 exceeds a certain limit. With a constant quantity 

 of substrate the relation between the catalase con- 

 centration and the reaction velocity is direct and 

 either logarithmic or linear, depending upon the 

 presence or absence of an excess of peroxide. 

 With a constant ratio between catalase and hy- 

 drogen peroxide the reaction velocities tend to 

 approximate each other. Three types of curves are 

 obtained when the reaction velocity is plotted 

 against time: first, of rare occurrence, a curve 

 showing a temporary increase in the value of K 

 followed after one or two minutes by a slow fall- 

 ing off; second, a curve showing a continuous fall- 

 ing off, which is the most common and the one 

 obtained when the catalase is in excess of the 

 peroxide; third, a curve represented by a straight 

 line, as is required by the monomolecular reaction, 

 when the hydrogen peroxide is greatly in excess of 

 the catalase. 



The action of 'proteins on the phenol reagent of 

 Folin and Dennis: Victor E. Levine. The phos- 

 photungstic-phosphomolybdio reagent of Folin 

 and Dennis is not specific for the phenolic group. 

 The reagent can not serve as a test for pro-teias 

 yielding tyrosine or hydrolysis, for all the proteins 

 tested including gelatine give positive reactions. 



