114 THE LAWS OF ORGANIC 



we have then a class of diseases called passive 

 Hcemorrhagies. 



CXIV. The effects of this venous plethora of Dr 

 CULLEN are precisely the same that we should 

 anticipate to happen from a knowledge of the 

 general changes in the circulation, as stated in 

 this chapter ; and it is for the reflecting reader to 

 judge, whether the present coincidence ought to 

 be regarded as confirming the views which I 

 have attempted to establish. 



CXV. In old age the motions of the heart are 

 less forcible ; the capillary system of the lungs 

 less vascular ;* and the ability or disposition to 

 exertion is diminished. It is therefore manifest 

 that the blood is propelled with less energy by the 

 influence of its moving powers throughout the 

 system. The properties of the vital fluid are 

 also less stimulating ; and these conditions, com- 

 bined with the comparative inactivity of the 

 body, are well calculated to augment the natural 

 internal determination of the sanguineous fluid. 

 But we are not to suppose that the system in the 

 decline of life contains the same quantity of blood 

 which it did in its prime ; the more confined 

 operation of those organs necessary to digest and 



* En examinant les cellules du poumon, j'ai etc frappe de la 

 variation de grandeur qu'elles eprouvent par les progres de 

 1'age 5 leur nombre est en raison inverse des annees. II resulte 

 de ce fait que notre poumon doit acquerir, a measure que nous 

 vieillissons, une legerete specifique tres grande. Journal de 

 Physiologic Experimentale. Par F. MAGENDIE. 4th Number. 

 October, 1821. /?, 80. 



