ARCHITECTURE OF THE SKULL 9 



Further thoughts might suggest that, whilst 

 the case should be made firm to resist a sharp 

 point, the vibrations of that circular case might 

 be prevented by lining it with a softer material ; 

 no bell would vibrate with such an incumbrance ; 

 the sound would be stopped like the ringing of a 

 glass by the touch of a finger. 



If a soldier's head be covered with a steel cap, 

 the blow of a sword which does not penetrate will 

 yet bring him to the ground by the percussion 

 which extends to the brain ; therefore, the helmet 

 is lined with leather and covered with hair ; for, 

 although the hair is made an ornament, it is an 

 essential part of the protection : we may see it 

 in the head-piece of the Roman soldier, where all 

 useless ornament, being despised as frivolous, was 

 avoided as cumbrous. 



We now perceive why the skull consists of two 

 plates of bone, one external, which is fibrous 

 and tough, and one internal, dense to such a 

 degree that the anatomist calls it tabula vitrea 

 (the glassy table). 



Nobody can suppose this to be accidental. It 

 has just been stated that the brain may be injured 

 in two ways : a stone or a hammer may break the 

 skull, and the depressed part of the bone injure 

 the brain ; whilst, on the other hand, a mallet 

 struck upon the head will, without penetrating, 

 effectually deprive the brain of its functions, by 



