290 THE LAWS OF ORGANIC 



es more blood. This reasoning is evidently fal- 

 lacious. If we suppose the enlarged cavity to 

 receive an ounce of blood, instead of half this 

 quantity in its natural condition, each superficial 

 particle of this fluid, as in ordinary cases, will be 

 applied to a given point of the internal surface, 

 and will act on this point as if the cavity were 

 only half the size. The contractions of the heart 

 may be regarded as made up of an infinity of 

 smaller motions, arising from the innumerable 

 particles of blood : therefore, one cavity twice 

 the size of another, supposing equality in every 

 other respect to exist, cannot possess a greater 

 proportional stimulus, or exercise a more ener- 

 getic action. If it contained a greater propor- 

 tional quantity of blood, and were on that ac- 

 count more excited, the muscular fibres would 

 exhibit greater strength in their contractions; 

 but these are slow, and feeble even in the state of 

 palpitation, compared to those of the naturally 

 organized heart when inordinately stimulated. 



CCCXV. Diseased valves may be regarded as 

 the cause of almost every change of structure 

 that affects the heart ; their extreme delicacy dis- 

 poses them to suffer from every irregularity of 

 action in the sanguiferous system ; and when dis- 

 ordered, their importance makes them readily 

 produce derangement of function, or structural 

 disorganization in other parts near and remote. 

 If they become cartilaginous or ossified, or if 



