304 THE LAWS OF ORGANIC 



every one of the above causes which occasion 

 Syncope. It is observed by a physiologist of 

 considerable talent, that " whatever increases or 

 lessens the vigour of one part must increase or 

 lessen the activity of the whole ; though the tem- 

 perature of the heart itself be no way affected, its 

 irritability is instantly diminished."* 



CCCXXXV. The irritability of the heart can- 

 not immediately be influenced by the increased 

 or diminished vigour or activity of one part of 

 the system ; its action may be excited or de- 

 pressed, but this will arise from the changes 

 of its natural stimulus, the blood. If this be 

 highly stimulating, its motions will be accelerated; 

 if deprived of its usual invigorating qualities, its 

 frequent and small pulsations will indicate, that 

 such is the state of the circulating fluid, and not 

 that the irr it ability of the organ itself is so far 

 lessened as to be the cause of this difference. 



CCCXXXVI. It is imagined, when the heart 

 ceases to contract, that it continues quiescent 

 until it has recovered its accustomed energy to 

 enable it to propel its contents. This idea is bor- 

 rowed from observations connected with other 

 phenomena of the system. Repose to a moderate 

 extent refreshes and strengthens our mental and 

 physical powers ; and from these facts we con- 

 clude, that repose will also be attended by simi- 

 lar consequences to the heart. 



* Dr KELLIE, Edinburgh Medical Journal, Vol. 1. p. 508. 



