NATUEE AND CAUSATION. 407 



also follows such operations as amputation of the tail and 

 castration. The period of accession is various, sometimes early, 

 often delayed, seldom occurring later than twenty days after 

 the reception of the injury. 



During the course of my experience the apparently most 

 fertile source of traumatic tetanus has been the occurrence, 

 not of extensive wounds, but rather of such as might at first 

 appear comparatively trifling. Most of these wounds were of 

 a character to induce pain, being chiefly severe punctures 

 amongst the muscles of the croup, thigh, fore-arm, or feet, 

 situations where the structures are all bound by strong and 

 unyielding tissues ; or when merely superficial or little more, 

 as broken knees, and saddle -galls, were, from their situation 

 and liability to abrasion and irritation, acting as a steady 

 source of disturbance. 



As respects docking — nicking, it is hoped, is now unknown 

 — and castration, which more frequently than any other opera- 

 tions are followed by tetanus, I do not think that we can with 

 certainty indicate the individuals in which the disease is likely 

 to ensue, nor yet say with certainty that any one mode of 

 performing these operations is, of all others, to be chosen as 

 being perfectly free from such disagreeable consequences. Still, 

 I am free to confess that the greater number of cases which I 

 have seen following these operations have, in the case of 

 docking, ensued where ligature and severe cauterization were 

 employed to arrest haemorrhage ; and in castration, when the 

 operation was carried out by means of caustic clams. 



Regarding the appearance of tetanus apart from wounds or 

 injuries, very appreciable causes are exposure to extremes of 

 climatic influence and to fatigue, more particularly if these are 

 associated with insuflicient food and improper sanitary con- 

 ditions. Intestinal irritation, either from the presence of foreign 

 and indigestible material, or intestinal parasites, I am satisfied 

 in certain cases is caj)able of inducing the diseased action ; 

 uterine disorders are also similarly blamed — of this, however, 

 I cannot speak corroboratively, but see no good reason to 

 doubt its truth. That cold and exposure suddenly encountered 

 have a determining influence in the production of tetanus we 

 occasionally see exhibited on an extensive scale in the case of 

 newly-shorn sheep, where, should a lowering of the tempera- 



