ON THOUGHT IN MEDICINE. 217 



thesis of binding and loosing, it was necessary to dis 

 cover the law of the conservation of force. 



The second half of the previous century was too 

 much possessed by the principles of rationalism to recog- 

 nise openly Stahl's 'soul of life.' It was presented 

 more scientifically as vital force, Vis vitalis, while in 

 the main it retained its functions, and under the name 

 of ' Nature's healing power ' it played a prominent part 

 in the treatment of diseases. 



The doctrine of vital force entered into the patho 

 logical system of changes in irritability. The attempt 

 was made to separate the direct actions of the virus 

 which produce disease, in so far as they depended on 

 the play of blind natural forces, the symptomata morbi, 

 from those which brought on the reaction of vital force, 

 the symptomata reactionis. The latter were princi- 

 pally seen in inflammation and in fever. It was the 

 function of the physician to observe the strength of 

 this reaction, and to stimulate or moderate it accord- 

 ing to circumstances. 



The treatment of fever seemed at that time to be 

 the chief point ; to be that part of medicine which had a 

 real scientific foundation, and in which the local treat- 

 ment fell comparatively into the background. The the- 

 rapeutics of febrile diseases had thereby become very 

 monotonous, although the means indicated by theory 

 were still abundantly used, and especially blood-letting, 



