274 STABLE MANUAL AND HORSE DOCTOR 



development. Insanity, in the sense of human medicine, 

 does not exist in the horse, whose sensorium is not affected 

 by causes of a social or moral nature ; though his brain 

 may be affected, as the centre of the nervous system, by 

 wounds and irritating disorders, through what we now 

 know as " reflex nervous action.'' Its sympathy and con- 

 nection with the stomach is also clear. The brain is 

 disordered by severe indigestion ; and a violent blow upon 

 the stomach, or that organ seriously overloaded, may give 

 rise to what is called " stomach staggers " — a decided 

 cerebral attack. Tetanus, or locked jaw, from wounds, is 

 also another example of reflex nervous irritation. A horse 

 pricks his foot with a nail, and tetanus is sometimes the 

 result. The spinal marrow, which is a continuation of the 

 substance of the brain, exhibits clearly the same nervous 

 mechanism. Division or injury of the marrow produces 

 loss of sensation and voluntary motion in those parts only 

 which derive their nerves from it beyond (or below) the 

 part injured or divided. 



Notwithstanding the brain is the source of all sensation, 

 it is, in itself, destitute of feeling. In operations on living 

 animals it has been pricked, lacerated, cut, even burnt, 

 without any manifestation of pain. We remember having 

 heard the late John Abernethy mention a case where a man 

 lost two ounces of brain by an accident, and lived many 

 years, at the head of a mercantile establishment, with 

 apparently unimpaired faculties. 



Pressure and Concussion^ however, have serious effects. 

 A portion of bone depressed from above prostrates the 

 animal and destroys life ; not so laterally, or from the side ; 

 and pressure on the spinal cord produces paralysis behind 

 the part so interfered with. 



Injuries of the Brain are not frequent in the horse, though 

 backward falls and blows are not uncommon, owing to the 

 immense strength of the parietes or walls of the skull. 



Concussion, so fatal to man, with his higher organisation, 

 produces nothing more than fright or giddiness. A bleeding, 

 a cooling draught, and a warm fomentation to the occiput, 

 will generally dispose of this apparently dangerous accident. 

 Fracture of tlte Skull, for the same reasons, is rarely seen 

 unless at the base, or basilary process. There is in most 

 cases more danger of blood-vessels giving way than bone, 

 even in these heavy concussions. Unless abscess of the 



