NATURE AND CAUSATION. 421 



whole, as rosults of the general or systemic declaration of 

 some wide-spread morbid condition ; and probably this is the 

 light in which not only epilepsy but several other of the 

 diseases affecting the nervous system ought to be regarded. 



Experimental researches prove that epileptic or epileptiform 

 seizures are capable of being induced by various and particular 

 interferences with certain portions of the brain-structure, and 

 of the anterior parts of the spinal cord, as also by removal of 

 the kidneys. From this we may be guided not to look upon 

 one, and only one, cause as sufficient to induce the peculiar 

 convulsive attacks recognised as epilepsy or epileptic, but 

 rather to give each individual case a careful consideration, as 

 well during the intervals between the paroxysmal seizures as 

 while these continue. 



From all that has been accomplished in this direction we 

 are assured of this, that, as yet, neither the cause nor the 

 exact elemental changes connected with true or idiopathic 

 epilepsy have been satisfactorily demonstrated. Although 

 in many instances of epileptiform seizures, obvious textural 

 change may be detected, there are still very numerous cases 

 where these same phenomena are exhibited apart from de- 

 tectable structural or elemental change in nervous matter, 

 and that, should change be discoverable, it has still to be 

 determined whether such is primarily of the true nervous 

 elements or of some others associated with them. 



Symptoms. — The severity of the epileptiform fits being liable 

 to so much variation, the train of symptoms is necessarily in 

 some less distinctly developed than in others. The premoni- 

 tory warning or aura, indicative of the approach of a fit, so 

 well recognised in man, we, in our patients, are of course unable 

 to appreciate or turn to advantage, although, from certain ex- 

 periments, there seems sufficient reason for believing in the 

 existence of such in animals other than human. In horses 

 under observation, the first indication of the fit is usually in- 

 terference with motorial activity, a staggering gait, an unmean- 

 ing stare, champing of the jaws, followed by rapid loss of 

 consciousness, and falling to the ground in convulsions. In 

 slight cases, the convulsive movements after the animals come 

 to the ground are of the most transient nature and feebly 

 expressed, confined, it may be, to one limb, or the muscles of 



