PHYSIOLOGY OF THE CIRCULATION. 107 



being, moreover, this additional advantage, that the 

 progress of the experiment was less liable to be dis- 

 turbed by effusion during any slight disorder of the 

 apparatus. 



The whole of these considerations will, I trust, be 

 deemed sufficient to establish the principle, that a 

 stream, while traversing a flaccid membranous tube, 

 can, under certain favourable conditions, exercise an 

 absorbing poiver ; and if the correctness of this state- 

 ment be admitted, it will not be difficult to reconcile 

 these views with the knowledge already possessed 

 on the subject of the process of absorption in animals ; 

 for as it is fully proved that the act of circulation, 

 or, in other words, the passage of the blood through 

 the minute vessels of the part, is essential to the 

 occurrence of absorption, it now only remains to 

 inquire, 1st, what particular part of the circulating 

 system is the more especial seat of this function, and 

 2ndly, in what manner the passage of external fluids 

 into the blood-vessels is accomplished. 



I may, however, previously remark, that, by thus 

 referring the active absorbing power to the streams 

 of blood, we are at once furnished with a satisfactory 

 explanation of the fact, that the circulation through 

 a part is necessary for the occurrence of an appreci- 

 able amount of absorption. 



In answer to the first question, I may repeat the 

 statement incidentally made when speaking of the con- 

 ditions essential to absorption, viz. that this action is 

 confined to the terminating portion of the capillaries 

 and the small veins. In support of this opinion may 

 be mentioned, 



