Chapter XVI 



The Circulation of the Blood is Supported by 

 its Implications 



ASSUMING the truth of this proposition there 

 *- are certain consequences which are useful 

 in coaxing belief a posteriori. Although some of 

 them may seem to be clouded in considerable doubt, 

 a reasonable case may easily be made for them. 



How does it happen that in contagious condi- 

 tions like poisoned wounds, bites of serpents or 

 mad dogs, or lues, the whole body may become 

 diseased while the place of contact is often un- 

 harmed or healed? Lues commonly appears at 

 first with pain in the shoulders and head, or by 

 other symptoms, the genitals meanwhile being 

 uninjured. We know that the wound made by a 

 mad dog may have healed when fever and the rest 

 of the unpleasant symptoms supervene. Without 

 doubt it happens that the contagion, first being 

 deposited in a certain spot, is carried by the re- 

 turning blood to the heart, from which later it is 

 spread to the whole body.^ 



^ The usual drainage from the tissues is now considered to be 

 through the lympathics. These pass through nodules of lymphoid 

 tissue in which "the contagion," — bacteria or other foreign bodies, — 



[io8] 



