Sect. XII. 5. 6. AND EXERTION. 67 



production of our ideas, or fenfual motions, when they are too 

 weakly excited ; when any one is thinking intenfely about one 

 thing, and carelefsly- converting about another, he is liable to ufe 

 the word of a contrary meaning to that which he defigned, as 

 cold weather for hot weather, fummer for winter. 



6. A certain quantity of ftimulus, lefs than that above men- 

 tioned, is fucceeded by paralyfis, firftof the voluntary and fenfi- 

 tive motions, and afterwards of thofe of irritation and of afiocia- 

 tion, which conftitutes death. 



VI. Cure of increafed Exertion. 



I. The cure, which nature has provided for the increafed ex- 

 ertion of any part of the fyftem, confifts in-the confequent ex- 

 penditure of the fenforial power. But as a greater torpor fol- 

 lows this exhauftion of fenforial power, as explained in the next 

 paragraph, and a greater exertion fucceeds this torpor, the con- 

 ftitution frequently finks under thefe increaling librations be- 

 tween exertion and quiefcence ; till at length complete quief- 

 cence, that is, death, clofes the fcene. 



For, during the great exertion of the fyftem in the hot fit of 

 fever, an increafe of ftimulus is produced from the greater mo- 

 mentum of the blood, the greater diftention of the heart and ar- 

 teries, and the increafed production of heat, by the violent ac- 

 tions of the fyftem occasioned by this augmentation of ftimulus, 

 the fenforial power becomes diminifhed in a few hours much 

 beneath its natural quantity, the veffels at length ceafe to obey 

 even thefe great degrees of ftimulus, as fhewn in Seel:. XL. 9. 

 I. and a torpor of the whole or of a part of the fyftem enfues. 



Now as this fecond cold fit commences with a greater defi- 

 ciency of fenforial power, it is alfo attended with a greater defi- 

 ciency of ftimulus than in the preceding cold fit, that is, with lefs 

 momentum of blood, lefs diftention of the heart. On this ac- 

 count the fecond cold fit becomes more violent and of longer 

 duration than the firft ; and as a greater accumulation of fenfo- 

 rial power muft be produced before the fyftem of veffels will 

 again obey the diminifhed ftimulus, it follows, that the fecond 

 hot fit of fever will be more violent than the former one. . And 

 that unlefs fome other caufes counteract either the violent exer- 

 tions in the hot fit, or the great torpor in the cold fit,- life will 

 at length be extinguished by the expenditure of the whole of the 

 fenforial power. And from hence it appears, that the true 

 means of curing fevers muft be fuch as decreafe the action of 

 the fyftem in the hot fit, and increafe it in the cold fit ; that is, 



fuch 



