FEVERS. 499 



trine of Fever as depending upon the inequality of the Excite- 

 ment or Collapse of the brain. 



" We know that in fevers a debility lays the foundation of 

 the disease, or that there takes place a diminution of the ex- 

 citement or energy of the brain, which even sometimes proceeds 

 to a deeper state of collapse, or to what is termed Coma, or a 

 disposition to sleep. This collapse is unequal with respect to the 

 different parts, and continues great with respect to the animal 

 functions, while it is recovered from with respect to the vital. 

 At the same time, the impetus of the blood is increased, which 

 is a powerful cause of excitement ; and some degree of collapse 

 at the same time taking place, this will readily give a delirium, 

 such as occurs in the hot fit of fevers. Or when there is an ex- 

 cess of collapse from the sedative operation of the remote causes, 

 and some cause of excitement is applied, as the impetus of the 

 blood in the ordinary course of circulation, such a delirium may 

 occur as that which frequently takes place in the cold fit of 

 fevers. It appears, then, that the inequality of the excitement 

 of the brain lays the foundation of delirium, which therefore 

 may be of two kinds, as it may either depend upon the excess 

 of excitement, or upon the excess of collapse. 



" Now there is no doubt that this explanation will suffi- 

 ciently account for all the transitory deliria that happen in the 

 cold fit of intermittent fevers ; and I do think that it will also 

 account for many of the instances of it which occur in continued 

 fevers, where it takes place without any topical affection of the 

 circulating organs of the brain, and where it appears to depend 

 entirely upon the states of excitement and collapse of the 

 nervous system, and to proceed from causes immediately affect- 

 ing it, independently of the state of the sanguiferous system. 



" But indeed these causes producing delirium, whether more 

 durable or more transitory, are not the only causes which pro- 

 duce this effect ; for in fevers the brain may also be topically 

 affected, which may be the cause of excitement and collapse 

 greater than would arise from the general state of fever. Thus 

 a degree of topical inflammation of the brain may take place, 

 so as to give more or less of the phrenitic delirium, from which 

 circumstance it will be more obstinate, or there may be other 



