116 PATHOLOGY 



legal purposes, and for the study of the genetic relationships of cer- 

 tain animals, a study that in the hands of Nuttall has given results 

 of general chemico-biological interest from an evolutional point of 

 view. 



Reviewing these remarkable developments one is profoundly 

 impressed with the fact that at the same time as they constitute 

 a most important widening-out of biochemical science they have 

 added greatly indeed to the permanent resources of practical medi- 

 cine, emphasizing again in the clearest way the everlasting identity 

 of the scientific and the practical. Let no one, at least in the medical 

 profession, ever doubt the practical value of the knowledge that 

 ripens on the tree of science! These developments also demonstrate 

 that there are other modes of progress toward knowledge of cellular 

 activity and biological mechanisms under pathological as well as 

 normal conditions than the purely morphologic highway which 

 hitherto had been followed with great persistence in pathology. 



Here we are dealing with chemical substances and chemical and 

 physical processes which ultimately will be interpreted in terms of 

 chemistry and physics. Already Arrhenius and Madsen have at- 

 tempted to show that the laws of mass-action and chemical equi- 

 librium govern the reactions between toxin and antitoxin, an 

 attempt that has precipitated a sharp controversy with the Ehrlich 

 school which cannot but powerfully stimulate continued work in 

 this field. Recently we have learned too that many salts in ionizable 

 solutions and also more complex substances combine in such a way 

 with the complements in normal and immune serums as to hinder 

 the union of complement and amboceptor necessary for lytic action. 

 Perchance it is in this direction that we may look for some insight 

 into the changes in physiological mechanisms that permit various 

 organisms to enter and set up disease. 



It seems that in the chemistry of immunity we soon may expect 

 most interesting developments. The fact that lecithin may act as 

 complement, that it forms a crystallizable "lecithid" by union with 

 the hemolytic amboceptor of snake-venom, and further, the evi- 

 dence now at hand that colloidal silicic acid may play the part of 

 amboceptor, warrant the hope that before long complete analysis, 

 and perhaps even synthesis, of lysins may become possible. 



The Synthesis of Different Methods in Scientific and Practical Medicine 



In the majority of cases we owe our first knowledge of the exist- 

 ence of distinct diseases to clinical observation. By keen study 

 physicians were able to distinguish even between more or less 

 similar pictures, but the clinical picture has not always proved 

 adequate for the determination of disease-entities. The clinical 



