PROCEEDINGS. 117 



ing and turning in a contrary manner toward the opposite side. 

 The blows against the chin on one side yielded the same effect as 

 if against the occiput on the other side. The transmission of 

 violence from one side of the chin to the opposite side of the upper, 

 back portion of the brain was named and explained as rotary trans- 

 mission and delivery, viewing the head mechanically as a two-armed 

 hollowlever and as an irregular wheel on the vertebral axis, the chin 

 terminating one lever arm while the brain is contained in the other 

 arm, the seat of locomotor control being in that part of the brani 

 which is in the lever end farthest from the chin, as indicated in 

 sketches shown. The effect there on one side of the brain inhibi- 

 ited the use of the leg of the opposite side, &c. Some contre-coup 

 injuries were similarly explained. The importance of the study 

 of these and certain related principles, their application, and the 

 practice of jarring to produce deep effects in the treatment of head 

 maladies was urged. 



