DISEASES OF THE HEAD AND NECK. 



283 



The treatment of a ease of this description is a matter of some 

 difficulty. The sinuses must be probed into and laid open to 

 their very base, and the whole dressed with a solution of the 

 bichloride of mercury — mercury, four drachms; water, four 

 ounces. The linings of the sinus will thus be destroyed and the 

 whole converted into a common wound. Where there is but one 

 sinus, and that a deep one, a seton may be inserted in the original 

 opening and brought out on the side of the jioll. 



In some cases where neglected, the disease involves the syno- 

 vial membrane of the occipito-atloidean articulation, causing 

 anchylosis of the joint. In some cases it penetrates the capsules 

 of the cervical vertebrae, causing sudden death by pressure upon 

 the medulla spinatis. 



FISTULOUS WITHERS. 



Fistulous withers resembles poll evil in all particulars except 

 its seat. It is caused by bruises from ill-fitting saddles. The 



Fig. 75 — Fistulous Withers. 



treatment is the same as for i)oll evil — namely, to make a depend- 

 ing orifice for the drainage of the pus, and the sinuses laid open, 

 or counter openings made by setons. 



