332 DISEASES CLASS III. 2. M; 



stimulus of vinous spirit; which, may properly be termed irri- 

 tative paralysis of those parts of the system. 



In the same manner in common palsies the inaction of the 

 paralytic muscle seems not to be owing to defect of the stimu- 

 lus of the will, but to exhaustion of sensorial power. Whence 

 it frequently follows great exertion, as in Sect. XXXIV. 1. 7. 

 Thus some parts of the system may cease to obey the will, as in 

 common paralysis; others may cease to be obedient to sensation, 

 as in the impotency of age; others to irritation, as in scirrhous 

 viscera; and others to association, as in impediment of speech; 

 yet though all these may become inexcitable, or dead, in respect 

 to that kind of stimulus, which has previously exhausted them, 

 whether of volition, or sensation, or irritation, or association, 

 they may still in many cases be excited by the others. 



SPECIES. 



1. Lassitudo. Fatigue or weariness after much voluntary ex- 

 ertion. From the too great expenditure of sensorial power the 

 muscles are with difficulty brought again into voluntary con- 

 traction; and seem to require a greater quantity or energy of vo- 

 lition for this purpose. At the same time they still remain obe- 

 dient to the stimulus of agreeable sensation, as appears in tired 

 dancers finding a renovation of their aptitude to motion on the 

 acquisition of an agreeable partner: or from a tired child riding 

 on a gold-headed cane, as in Sect. XXXIV. 2. 6. These mus- 

 cles are likewise still obedient to the sensorial power of associa- 

 tion, because the motions when thus excited, are performed in 

 their designed directions, and are not broken into variety of ges- 

 ticulation, as in St. Vitus's dance. 



A lassitude likewise frequently occurs with yawning at the 

 beginning of ague-fits; where the production of sensorial pow- 

 er in the brain is less than its expenditure. For in this case the 

 torpor may either originate in the brain, or the torpor of some 

 distant parts of the system may by sympathy affect the brain ? 

 though in a less proportionate degree than the parts primarily 

 affected. 



2. Facillatio senilis. Some elderly people acquire a see-saw 

 motion of their bodies from one side to the other, as they sit. 

 like the oscillation of a pendulum. By these motions of the mus- 

 cles, which preserve the perpendicularity of the body, are alter- 

 nately quiescent, and exerted; and are thus less liable to fatigue 

 or exhaustion. This therefore resembles the tremors of old 

 people above mentioned, and not those spasmodic movements of 

 the face or limbs, which are called tricks, described in Class IV 



