SECT. VIL. PHYSIOLOGY. 67 
. cLut. It has been shown that re-action seldom 
occurs in the cholera of India, owing to the too 
great afflux of blood to the viscera; in tetanus it 
also rarely happens, because there is little or no 
determination to the cavities. 
cLiv. Convulsion is distinguished from spasm 
by the muscles being agitated by alternate con- 
traction and expansion without the concurrence 
of volition. Convulsion may be either general, 
as in epilepsy, or local, as in asthma, or the te of 
the French authors. Convulsion may be symp- 
tomatic in all diseases which terminate in death, 
but the observations which I have to offer, will be 
confined chiefly to idiopathic convulsive disorders. 
civ. Epileptic convulsions. — Areteus calls 
epilepsy a disease of the brain, as one of the 
characteristic distinctions between it and tetanus. 
All the causes of epilepsy may very properly be 
classed after Cullen’s method, into sedative and 
stimulant causes. This disease is sometimes heredi- 
tary ; more commonly it arises from some severe 
shock received by the brain, which is at one time 
of a physical, and at another of a moral nature. 
cLvi. As epilepsy may be defined to be a sus- 
pension of the mental functions of the brain, toge- 
ther with a reducement of its vital force, it is 
not therefore to be inferred, that the brain is in 
a state. of excitement during an epileptic fit, 
although it may have been brought on by a 
