Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

ments, spasms, or convulsions. The spinal system is, in all its parts, excitor — excito-motor. These important facts constitute, according to him, the foundation of all our knowledge of the diseases of the nervous system, and are the very source of all diagnosis in regard to them. These facts hold good in regard to the living human body. By experiment and by observation, then, we are led to these conclusions: — 3. No lesion of the cerebral system, if limited to the cere- brum, can be attended by spasm or convulsion. 4. No structural lesion of the spinal system, short of absolute destruction, can possibly occur without exciting spasm or con- vulsion. If the destruction is complete, then there is palsy. If, in affections of the cerebral system, we observe spasm or convulsion, it is because it is not limited, in itself or in its effects, to the cerebral system. Thus congestion of the centre of the cerebral system may, as in hanging, become extended to that of the spinal system, and then spasm or convulsion appears. Again, affections of the spinal centre may consist of mere light or gently-applied pressure, not in absolute lesion of tis- sue ; and then paralysis, not spasm or convulsion, will be observed. Or it may consist in sudden or violent shock, or in utter destruction ; and then, I need scarcely say, paralysis, and not spasm or convulsion, will occur. All this we have seen demonstrated by experiment; all this you will see again and again in your observation in clinical practice, and especially in the surgical wards. What a means of diagnosis, then, have we obtained by these simple physiological facts! How has phys- iology become our guide in practice! I have thus explained to you how disease of the cerebral centre may, by pressure doicmcard, affect the spinal centre. But another question arises — How does a disease of the spinal system, as a pure convulsive malady, affect the cerebral ? — for such is a fre- quent event, as we observe in epilepsy. " Notice what occurs in the most marked cases of this dire malady. The head becomes fixed, or there is torticollis, by the action of the muscles of the neck — a trachelismus ; the jugu- lar and other veins of the neck are compressed ; the capillaries