14 BIOLOGY 



are chemical machines, made of essentially colloidal material, which 

 possess the peculiarity of developing, preserving, and reproducing 

 themselves automatically. The machines which have thus far been 

 produced artificially lack the peculiarity of developing, growing, 

 preserving, and reproducing themselves, though no one can say 

 with certainty that such machines might not one day be constructed 

 artificially. 



The specific and main work of the biologist will, therefore, be 

 directed toward the analysis of the automatic mechanisms of develop- 

 ment of self-preservation and reproduction. 



II. The Dynamics of the Chemical Processes in Living Organisms 



The progress made by chemistry, especially physical chemistry, 

 has definitely put an end to the idea that the chemistry of living 

 matter is different from the chemistry of inanimate matter. The 

 presence of catalyzers in all living tissues makes it intelligible that 

 in spite of the comparatively low temperature at which life phenom- 

 ena occur the reaction velocities for the essential processes in living 

 organisms are comparatively high. It has been shown, moreover, that 

 the action of the catalyzers found in living organisms can be imitated 

 by certain metals or other inorganic catalyzers. We may, therefore, 

 say that it is now proved beyond all doubt that the variables in the 

 chemical processes in living organisms are identical with those with 

 which the chemist has to deal in the laboratory. As a consequence of 

 this result chemical biology has during the last years entered into 

 the series of those sciences which are capable of predicting their 

 results quantitatively. The application of the theory of chemical 

 equilibrium to life phenomena has led biological chemists to look 

 for reversible chemical processes in living organisms, and the result 

 is the discovery of the reversible enzyme actions, which we owe to 

 A. C. Hill. I think it marks the beginning of a new epoch of the 

 physiology of metabolism that we now know that the same enzymes 

 not only accelerate the hydrolysis, but also in some cases, if not 

 generally, the synthesis of the products of cleavage. It is not im- 

 possible that the results thus obtained in the field of biology will 

 ultimately in return benefit chemistry, inasmuch as they may en- 

 able chemistry to accomplish syntheses with the help of enzymes 

 found in living organisms which could otherwise not be so easily 

 obtained. 



A very beautiful example of the conquest of biological chemistry 

 through chemical dynamics is offered by the work of Arrhenius and 

 Madsen. These authors have successfully applied the laws of chem- 

 ical equilibrium to toxins and antitoxins so that it is possible to 

 calculate the degree of saturation between toxins and antitoxins for 



