THEORY OF DISEASE. 249 



all the phenomena which they exhibit as conductors of 

 the vital force. In the present state of our knowledge, 

 no one, probably, will imagine that electricity is to be 

 considered as the cause of the phenomena of motion in 

 the body ; but still, the medicinal action of electricity, 

 as well as that of a magnet, which, when placed in con- 

 tact with the body, produces a current of electricity, 

 cannot be denied. For to the existing force of motion 

 or of disturbance there is added, in the electrical current, 

 a new cause of motion and of change in form and 

 structure, which cannot be considered as altogether in- 

 efficient. 



Practical medicine, in many diseases, makes use of 

 cold in a highly rational manner, as a means of exalting 

 and accelerating, in an unwonted degree, the change of 

 matter. This occurs especially in certain morbid con- 

 ditions in the substance of the centre of the apparatus 

 of motion ; when a glowing heat and a rapid current of 

 blood towards the head point out an abnormal metamor- 

 phosis of the brain. When this condition continues 

 beyond a certain time, experience teaches that all mo- 

 tions in the body cease. If the change of matter be 

 chiefly confined to the brain, then the change of matter, 

 the generation of force, diminishes in all other parts. 

 By surrounding the head with ice, the temperature is 

 lowered, but the cause of the liberation of heat contin- 

 ues ; the metamorphosis, which decides the issue of the 

 disease, is limited to a short period. We must not for- 

 get, that the ice melts and absorbs heat from the dis- 



