44 LECTURE I. 



and have therefore never become very widely diffused. 

 According to my notions, the basis of both doctrines is 

 an incomplete one ; I do not say a false one, because it 

 is really only false in its exclusiveness ; it must be 

 reduced within certain limits, and we must remember 

 that, besides vessels and blood, besides nerves and ner- 

 vous centres, other things exist, which are not a mere 

 theatre (Substrat) for the action of the nerves and blood, 

 upon which these play their pranks. 



Now, if it be demanded of medical men that they give 

 their earnest consideration to these things also ; if, on 

 the other hand, it be required that, even among those 

 who maintain the humoral and neuro-pathological doc- 

 trines, attention at last be paid to the fact, that the blood 

 is composed of many single, independent parts, and that 

 the nervous system is made up of many active individual 

 constituents this is, indeed, a requirement which at the 

 first glance certainly offers several difficulties. But if 

 you will call to mind that for years, not only in lectures, 

 but also at the bedside, the activity of the capillaries 

 was talked about an activity which no one has ever 

 seen, and which has only been assumed to exist in com- 

 pliance with certain theories you will not find it unrea- 

 sonable, that things which are really to be seen, nay are, 

 not unfrequently, after practice, accessible even to the 

 unaided eye, should likewise be admitted into the sphere 

 of medical knowledge and thought. Nerves have not 

 only been talked about where they had never been 

 demonstrated ; their existence has been simply assumed, 

 even in parts in which, after the most careful investiga- 

 tions, no trace of them could be discovered, and activity 

 has been attributed to them ip. parts where they abso- 

 lutely do not penetrate. It is therefore certainly not 

 unreasonable to demand, that the greater part of the 

 body be no longer entirely ignored ; and if no longer 



