ACTIVE HYPER^MIA. 151 



relaxation of its muscular fibres, be produced directly 

 by a paralysis of the nerve or an interruption of the 

 nervous influence, or whether it be the indirect result of 

 a previous stimulation, giving rise to exhaustion that, 

 I say, in every case we have to deal with a kind of 

 paralysis of the walls of the vessel, and that the process 

 is incorrectly designated active hyperaemia, inasmuch as 

 the condition of the vessels in it is always a completely 

 passive one. All that has been built up upon this 

 assumed activity of the vessels, is, if not exactly built 

 upon sand, still of an extremely ambiguous nature, and 

 all the conclusions that have besides been drawn with 

 regard to the important influence which the activity of 

 the vessels was supposed to have upon the conditions of 

 nutrition of the parts themselves, fall at the same time 

 to the ground. 



When an artery is really in action, it gives rise to no 

 hyperaemia ; the more powerfully it acts, the more does 

 it occasion anaemia, or, as I have designated it, ischcemia, 

 and the less or greater degree of activity in the artery 

 determines the greater or less quantity of blood which 

 in a unit of time can stream into a given part. The 

 more active the vessel, the less the supply of blood. If, then, 

 we have to deal with an hyperaemia the result of irrita- 

 tion, the most important point, therapeutically, is just 

 this : to place the vessels in such a state of activity as 

 will enable them to offer resistance to the onward rush 

 of blood. This we can accomplish by means of what is 

 called counter-irritation, a higher degree of irritation in 

 an already irritated part, stimulating the fatigued mus- 

 cular fibres of the vessel to persistent contraction, and 

 thereby diminishing the supply of blood and leading the 

 way to a regulation of the disturbance. In the very 

 cases in which reaction, that is, regulatory activity, is 

 most called for, the chief point is to overcome that state 



