680 OPERATIONS. 



bullet through the centre of the brain is almost always certain 

 death, even when the spinal cord Is not touched. A good and easy 

 plan for killing a horse with either pistol or gun, is to shoot him 

 in the middle line of the forehead, about four or five inches above 

 the level of the eyes ; for instance, in the centre of the " star " in 

 Fig. 175 (p. 681). The weapon should be held close to the fore- 

 head. If this be done, the animal will drop down, without a 

 struggle, on the spot upon which he has been standing. Or, 

 having opened the jugular vein, we may, by means of a tube, blow 

 air into the vein in the direction of the heart, when death will 

 ensue from suffocation (p. 651). 



A very easy and effective method of shooting a horse is by 

 means of Greener's "Humane Cattle Killer" (Fig. 176, p. 683), 

 which is an invaluable help in slaughter houses or when large 

 numbers of useless and disabled horses have to be destroyed, as 

 often happens, during war time. The fact of its being noiseless 

 greatly enhances its value in enclosed areas. 



Neurotomy (Neurectomy). 



In surgery, the operation of removing or cutting out a portion 

 of a nerve or nerves, which is almost always done with the object 

 of depriving the part of sensation, is termed neurectomy ; but in 

 popular language it is called neurotomy, signifying the mere 

 cutting of a nerve or nerves. It has special reference to sensory 

 nerves, which, like those of feeling, convey impressions inwards to 

 the brain and spinal cord ; the reply being transmitted outwards 

 by motor nerves. If, for instance, our hand receives a wound, its 

 sensory nerves convey the impression of pain to their nervous 

 centre, which thereupon excites the motor nerves of the hand and 

 arm to draw the limb back. If, in such a case, neurectomy of the 

 motor nerves of the part had been performed, pain would be felt, 

 but no response would be obtained from the muscles, which, as 

 a result of the neurectomy, would be in a paralysed condition. 

 If, on the contrary, neurectomy only of the sensory nerves had 

 been made, there would be no pain, and consequently no muscular 

 contraction; although the nerV^ous centre could cause movement 

 by acting on the motor nerves of the part. Hence, when a 

 horse is lame from an incurable disease which, like navicular 

 disease, renders movement painful, it is well to remove sensibility 

 by neurectomy. The operation will then have to be performed 

 on the sensory nerve or nerves, above the seat of pain, so that 

 no painful impression can be received by the nerve centre. If 

 the nerves be simply divided (neurotomy), the cut ends will unite 



