498 PROCEEDINGS OF SECTION D. 



responds to such a plienomenon as the neutralisation of a simple acid, 

 such as acetic acid, by a simple base. The experiments of Cooke (4 7), 

 also, upon the absorption of water by muscles placed in different concen- 

 trations of salts, lead to a similar conclusion. 



Summing up the results, therefore, derived from a consideration of 

 the influence of the concentration of an electrolyte upon living tissues, 

 we may say that the results are such as to suggest a chemical reaction, 

 but so simple a reaction as that represented by the neutralisation of a 

 simple monobasic acid by a simple monacid base. 



Finally, in continuing our analysis of the information regarding the 

 properties of the ion-proteid compounds, which has been so far derived 

 from a consideration of the properties and reactions of living tissues, we 

 may allude to the influence of temperature upon life-phenomena. 



Arrhenius (48) has shown that the velocity of a chemical reaction 



increases very much more rapidly with increasing temperature than any 



known physical phenomenon. The velocity of a chemical reaction 



increases about 10 per cent, per degree centrigade rise in temperature, 



while molecular velocity, the electric conductivity of a wire, the elasticity 



of a solid, the viscosity of a fluid, surface tension, &c., are much less 



affected by the same rise in temperature. 



rri .• 4. velocity of reaction at Tn. -4-10, ^^ j .■, . . 



ihe quotient ^ — -_ ' called the temperature 



velocity of reaction at Tn., 



coefficient of the reaction, is about two for a chemical reaction, Tn. 



being the absolute temperature. The temperature-coefficient for 



" absorption-combination," as, for example, the absorption of a dye by 



fllter-paper, is only about 1"36 (49). 



Kegarding the majority of life phenomena as directly or indirectly 

 dependent upon the reactions and properties of the ion-proteid com- 

 pounds, the effects of temperature upon life processes are of the greatest 

 interest. The experiments of Christen, quoted by Duclaux (50), on the 

 time of exposure to high temperatures required to kill the spores of 

 bacilli would indicate a temperature coefficient of at least four for this 

 process. The experiments of Lautenbach (51) on the influence of tem- 

 perature upon reflex time would indicate a temperature coefficient of 6 

 or 7. Clausen (52), ex])erimenting on the influence upon the production 

 of COo by seeds, found a temperature coefficient of 2-5. Hertwig (53), 

 experimenting on the influence of temperature upon the rate of develop- 

 ment of frogs' eggs, found a temperature coefficient of from 2 to 3. 

 Abegg (54), working on the production of carbon dioxide by frogs and 

 in other experiments, found temperature coefficients of about 2. CD. 

 Snyder (55), working under Dr. Loeb's direction, found a temperature 

 coefficient of about 2 for the influence of temperature upon the rate of 

 the beat in the heart of the terrapin. Loeb (56) has found that the 

 velocity of artificial maturation in the eggs of a mollusc f LottiaJ is 

 doubled or trebled by a rise in temperature of 10 degrees. I found (57) 

 that the average value of the temperature co-efficient for the rate of the 

 heart-beat in a crustacean /'Cerzo^/ayoAnmy' was 2'03 for about 25 to 30 

 determinations, none of which varied very far from the average. Burnett 

 (58) has found a temperature coefficient of from 2 to 3 for the shortening 

 of ihe latent period with rise of temperature in muscles stimulated 

 indirectly. 



