622 CIRCULATION OF THE ARTERIAL 



a ligature around the aorta, the blood has been 

 seen with a good microscope, to move with con- 

 siderable velocity through the capillaries of the 

 mesentery for thirty-five minutes, and in one case 

 for an hour and a quarter, as proved by the ex- 

 periments of Dr. Philip : 4. That in many cases 

 after death, and apparent cessation of the heart's 

 action, the large arteries have been found empty ; 

 all their blood having been conveyed to the veins 

 by capillary attraction : and, 5. That after the 

 amputation of a limb, and the stoppage of its ca- 

 pillary circulation, the motion of its blood maybe 

 restored, and carried on with considerable activity 

 for fifteen minutes, by the application of heat, as 

 proved by the experiments of M. Guiltot. (Jour- 

 nal de Physiologic, t. xi. p. 170.) 



It has been urged by De Saussure, Decandolle, 

 Tiedemann, and others, that the circulation in 

 plants and animals must be owing to a different 

 cause from that of ordinary capillary attraction, 

 because when their vessels are divided during the 

 living state, sap and blood continue to flow from 

 them; whereas the fluids drawn up by small 

 tubes of glass and other dead matter are not ex- 

 pelled from their upper orifices. But it should 

 be observed, that the force of capillary attraction, 

 ceteris paribus, is always inversely as the dia- 

 meter of the tubes, which are much smaller in 

 plants and animals than any employed in our ex- 

 periments. Hence the great force with which 



