400 Scientific Intelligence. Physiology. 



urination of the different elements which concur in effecting the 

 whole movement of the artery, such as the dilatation, locomo- 

 tion, &c. and consequently I have made it my first object to 

 ascertain the number and the nature of these elements. 1st, 

 The dilatation of Arteries. He then addresses himself to the de- 

 termination of the point, If an artery alternately dilates and 

 contracts during its motion ? He holds that the experiments 

 which are detailed in the memoir prove this double movement ; 

 whence the author concludes that dilatation is an attendant phe- 

 nomenon, and one of the elements in the movements of the ar- 

 tery. 2d, The locomotion of the Artery. As the result of his 

 experiments, the author moreover holds that the locomotive 

 movement of arteries strengthens, elevates, straightens, abases, 

 changes, and effaces the curves of arteries ; and hence he in- 

 fers that this locomotive movement is a second element in the 

 movement of the artery. 3d, The throb and elongation of the 

 Artery. To these movements of dilatation and locomotion M. 

 Flourens has observed that there is added a shock or jerking mo- 

 tion, which, by turns, carries the vessel from behind forwards, and 

 from before backwards, and this is the third element of the total 

 movement or beat of the artery. " These, then, he continues, 

 the dilatation, the locomotion, and the shock, are the three 

 primitive, constituent, and true elements of the whole move- 

 ments of the artery, as demonstrated by experiment. And 

 when, in physiology, we have, on the one hand, the constitu- 

 ent elements of a phenomenon, and, on the other, the organ 

 which executes this phenomenon, all that we can moreover do, 

 is to connect the elements of the phenomenon with the physical 

 qualities of the organ. Now, the physical quality which is the 

 most essential one of the arteries, in connection with the point 

 under review, is undoubtedly their elasticity. As a result of 

 this elasticity the artery can be distended in capacity, hence its 

 dilatation ; likewise in length, whence its elongation and throb ; 

 it can also be bent, straightened, displaced, &c., and hence its 

 locomotion ; and if we moreover remark, that in all these cases 

 it returns to its previous state, and by its own inherent power, 

 we have the whole variety of these motions reversed and alter- 

 nated ; and from all these together^ proceeds the total move- 

 ment or the beat of the artery. The beat then, or total move- 



