November 6, 1908] 



SCIENCE 



647 



on constantly in the heart. He suggested to me 

 that this idea could be tested by exact quantita- 

 tive determinations of the influence of temperature 

 upon the rate of the heart beat. We know through 

 Arrhenius how the velocity of a chemical reaction 

 •varies with the temperature. If the heart beat 

 were, as supposed, a function of a reaction velocity, 

 then the law of Arrhenius should also hold for 

 the influence of temperature upon the rate of the 

 heart beat. 



While Mr. Snyder was preparing his thesis 

 for the degree of Ph.D., Loeb suggested to 

 Maxwell that he should undertake the in- 

 vestigation of the influence of temperature 

 upon the velocity of the nervous impulse: 

 Maxwell, however, started work upon another 

 problem, and consequently Loeb asked Burnett 

 to undertake this investigation. Burnett's 

 investigation had not proceeded far when he 

 found it advantageous to study the influence 

 of temperature upon the latent period of 

 striated muscle. The result of this investiga- 

 tion was published early in 1906.* After- 

 wards, on account of pressure of other work, 

 Burnett was unable to continue the investiga- 

 tion, and, at Loeb's request. Maxwell carried 

 it through, and the results were embodied in 

 -the paper to which Mr. Snyder refers, in the 

 foot-note quoted above, as an encouraging 

 ■example of the extent to which his ideas have 

 been appropriated by members of this labora- 

 tory. Meanwhile Loeb had published his ob- 

 servations upon the temperature coefficient of 

 artificial maturation in Lottia^ and of the pro- 

 duction of artificial parthenogenesis by the ac- 

 tion of hypertonic sea water," and Robertson 

 had published his observations upon the 

 temperature coefficient of the heart beat in the 

 crustacean Daphnia.'' In his " conspectus of 

 the temperature coefficients of the velocities 

 ■of all the physiological actions determined up 

 to the present time," however, Mr. Snyder does 

 not refer to any of these papers, and, with 

 remarkable consistency, also fails to refer to 

 all papers upon the temperature coefficients of 

 life processes which contain extensive refer- 



* Journal of Biological Chemistry, 2, 1906, p. 

 195. 



" Univ. of Calif. Pull., Physiol., 3, 1905, p. 1. 



'hoc. cit., p. 40. 



^ Biol. Bulletin, 10, 1906, p. 242. 



ences to these publications, as, for example, 

 the paper on the influence of temperature 

 upon the refractory period in the sartorius 

 muscle of the frog, published by Bazett in the 

 Journal of Physiology, February, 1908. Mr. 

 Snyder is, however, undoubtedly familiar with 

 some of these publications, inasmuch as he has 

 inserted references to that of Loeb upon the 

 temperature coefficient of artificial maturation 

 and to that of Robertson upon the temperature 

 coefficient of the heart beat in Daphnia, in a 

 previous publication of his own.' 



Since Mr. Snyder's " conspectus of the tem- 

 perature coefficients of the velocities of all the 

 physiological actions determined up to the 

 present time " is singularly defective in other 

 respects, we here insert a list of the literature 

 on this subject which, to the best of our knowl- 

 edge is complete up to the present date. Save 

 those containing results originally utilized by 

 Cohen in calculating the temperature coeffi- 

 cients of life processes published in his " Phy- 

 sical Chemistry," all references to papers not 

 actually regarding the influence of tempera- 

 ture upon life phenomena from the point of 

 view of its influence upon chemical reaction 

 velocity, are omitted. We publish this list in 

 the hope, not only that it may be of use to the 

 student of this department of physiological 

 research, but also that it may serve to further 

 encourage Mr. Snyder by demonstrating to 

 him how widely his ideas have been adopted, 

 how many laboratories have thought well 

 enough of them to use them as a basis for 

 investigations and in how many cases these 

 ideas were, with remarkable prescience, util- 

 ized before Mr. Snyder had ever published his 

 " original communication,"' in which they 

 were so " clearly expressed " : 



Clausen: Landwirtsch. Jahrh., 19, 1890, p. 

 892. 



Hertwig, 0.: Arch. f. Mihrosh. Anat., 51, 

 1898, p. 319. 



Cohen, Ernst: "Physical Chemistry," 

 trans, by Fischer, New York, 1903, pp. 

 50-67. 



'Amer. Jour. Phys., 17, 1906, p. 350. 



'Arch, fiir Anat, und Physiol., Physiol. Abh., 

 1907, p. 113. 



