558 DECLINE OF THE SYSTEP>I. 



ployed to remove such parts as are no longer use- 

 ful ; and when all these adjustments have been 

 made, the functions still go on for a considerable 

 length of time without material alteration. 



The period prescribed for its duration being at 

 length completed, and the ends of its existence 

 accomplished, the fabric can no longer be sus- 

 tained, and preparation must be made for its inevi- 

 table fall. In order to form a correct judgment of 

 the real intentions of nature with regard to this last 

 stage of life, its phenomena must be observed in 

 cases where the system has been wholly entrusted 

 to the operation of her laws. When death is the 

 simple consequence of age, we find that the ex- 

 tinction of the powers of life observes an order 

 the reverse of that which was followed in their 

 evolution. The sensorial functions, which were 

 the last perfected, are the first which decay ; and 

 their decline is found to commence with those 

 mental faculties more immediately dependent on 

 the physical conditions of the sensorium, and 

 more especially with the memory, which is often 

 much impaired while the judgment remains in full 

 vigour. The next faculties which usually suffer 

 from the effects of age are the external senses ; 

 and the failure of sight and of hearing still far- 

 ther contributes to the decline of the intellectual 

 powers, by withdrawing many of the occasions 

 for their exercise. The actual demolition of the 

 fabric commences whenever there is a conside- 

 rable failure in the functions of assimilation ; but 

 the more immediate cause of the rapid extinction 

 of life is usually the impediment which the loss of 

 tlie sensorial power, necessary for maintaining the 



