422 PRACTICE OF PHYSIC. 



MCCXCIX. Physicians have found no difficulty in com- 

 prehending how direct stimulants, of a certain force, may excite 

 the action of the brain and occasion epilepsy ; but they have 

 hitherto taken little notice of certain causes which manifestly 

 weaken the energy of the brain, and act, as I speak, by collapse. 

 These, however, have the effect of exciting the action of the 

 brain in such a manner as to occasion epilepsy. I might, upon 

 this subject, speak of the vis medicatrix natures ; and there is 

 a foundation for the term : but, as I do not admit the Stahlian 

 doctrine of an administering soul, I make use of the term only 

 as expressing a fact, and would not employ it with the view of 

 conveying an explanation of the manner in which the powers of 

 collapse mechanically produce their effects. In the mean time, 

 however, I maintain, that there are certain powers of collapse, 

 which in effect prove stimulants, and produce epilepsy. 



MCCC. That there are such powers, which may be termed 

 Indirect Stimulants, I conclude from hence, that several of the 

 causes of epilepsy are such as frequently produce syncope, which 

 we suppose always to depend upon causes weakening the energy 

 of the brain (MCLXXVI.). It may give some difficulty to 

 explain why the same causes sometimes occasion syncope, 

 and sometimes occasion the reaction that appears in epilepsy ; 

 and I shall not attempt to explain it : but this, I think, does 

 not prevent my supposing that the operation of these causes is 

 by collapse. That there are such causes producing epilepsy, 

 will, I think, appear very clearly from the particular examples 

 of them I am now to mention. 



MCCCI. The first to be mentioned, which I suppose to be 

 of this kind, is haemorrhagy, whether spontaneous or artificial. 

 That the same haemorrhagy which produces syncope often at 

 the same time produces epilepsy, is well known; and, from 

 many experiments and observations, it appears, that haemorr- 

 hagies occurring to such a degree as to prove mortal, seldom do 

 so without first producing epilepsy. 



MCCCII. Another cause, acting, as I suppose, by collapse, 

 and therefore sometimes producing syncope and sometimes epi- 

 lepsy, is terror ; that is, the fear of some great evil suddenly 

 presented. As this produces at the same time a sudden and 

 considerable emotion (MCLXXX.), so it more frequently pro- 

 duces epilepsy than syncope. 



