JULT 1, 1904.] 



SCIENCE. 



13 



tions are involved; one of these has to do 

 with its formation in metabolism. The 

 other is a question of chemical equilibrium 

 at a given temperature. The first question 

 is the more difScult and also practically the 

 less important. The second question may 

 not prove difficult of solution. 



I have spoken of the great work of 

 Ehrlich and others in the development of 

 the doctrines of immunity and toxicity. 

 In the experimental examination of this 

 problem it was found that many reactions 

 between toxins and antitoxins can be car- 

 ried out in the test-tube, leaving for the 

 animal experiment certain final or crucial 

 reactions only. In other words, a large 

 number of important points in question 

 seem to be strictly chemical and must be 

 tested by chemical rather than by biological 

 methods. In deciding on the nature of 

 any given reaction taking place in solution 

 and requiring time for its completion a 

 determination of the so-called speed of the 

 reaction is often of value. It has been 

 shown that reactions taking place in one 

 direction and involving one, two or three 

 molecules follow certain definite schemes. 

 The behavior of some of the simple fer- 

 ments has been studied from this point of 

 view and lately it has been found possible 

 to submit the reaction between toxins and 

 antitoxins to this kind of mathematical 

 analysis. Something over a year ago 

 Arrhenius and Madsen published a very 

 important paper with the title: 'Applica- 

 tions of Physical Chemistry to the Study 

 of the Toxins and Antitoxins,' in which, 

 from the observations of Ehrlich, the essen- 

 tially chemical nature of these reactions 

 was shown. This paper was followed by 

 others by the same authors and also by 

 Ehrlich, who takes exception to some of the 

 physico-chemical generalizations, yet recog- 

 nizes the value of the mathematical treat- 

 ment. It is likely that this discussion is 

 but the beginning of the application of 



physical and mathematical chemistry in 

 the exact study of problems which at one 

 time were assumed to be essentially bio- 

 logical. I believe that medical science will 

 derive great benefit from this alliance, as a 

 means is here offered of testing the value 

 of many assumed working hypotheses. 

 There is a field here which is worthy of at- 

 tention and which certainly can not remain 

 long unoccupied. Many reactions taking 

 place normally in the body will be found 

 to lend themselves readily to the physico- 

 chemical treatment and the applications in 

 pathology will also appear as the methods 

 become better understood. 



Many medical men are beginning to 

 recognize the value of this line of inquiry 

 in the development of research, and the 

 question is often asked how may the 

 practitioner of medicine make himself 

 familiar enough with the new physico- 

 chemical theory to derive any benefit from 

 it. This is admittedly a difficult question. 

 "With the student of medicine, however, the 

 case is difllerent. He may be given from 

 the start the proper training to enable him 

 to understand something of the drift of 

 this new chemistry, if not to practise it 

 readily. An opinion has been cultivated 

 for years in some of our medical schools 

 that the only part of chemistry really im- 

 portant for the physician is the organic 

 chemistry of the food stuffs and their meta- 

 bolic products. This is an extremely nar- 

 row conception of the case and it has often 

 led to a neglect of those branches of gen- 

 eral and physical chemistry through which 

 the foundation principles of the science 

 may be most satisfactorily presented. With 

 the growing importance of the applications 

 of physical chemistry in medicine the chem- 

 ical training of the medical man will have 

 to be correspondingly advanced, and of 

 necessity the foundation work in this train- 

 ing will have to be done in the freshman 

 and sophomore years of our scientific 



