298 



Diseases of Sheep. 



I have no hesitation in sayings that in the few instances in which 

 the rude operations employed for this purpose have been success- 

 ful, it is to be attributed more to accident than to skill. If it 

 were possible to ascertain with certainty the exact position of the 

 vesicle, the operation of trepanning might be safely resorted to. 

 Mr. Smith, of Southam, is said to have repeatedly performed this 

 operation successfully.* It is to be done by making two incisions, 

 so as to form, when united, the letter T over the somewhat 

 softened part of the skull, supposed to cover the hydatid. Turn- 

 ing the angles of the skin back, by dissecting them from the 

 bone, the latter is now to be pierced by a trephine, and the portion 

 of bone removed. This done, the brain will be exposed, and the 

 hydatid, if at the part, will rise up covered by the dura mater : 

 this must also be cut through and turned back, and the parasite 

 punctured with a fine curved needle carrying a thread. As soon 

 as it has shrunk up it may be gently dravv^n away by means of the 

 thread, and the dura mater and skin replaced over the part ; the 

 edges of the latter being held together by a stitch or two, and 

 covered with a cap. The portion of the bone must not be re- 

 turned. A very rude, and, although I have practised it myself, 

 I must say cruel operation, allied to the trepanning principle, has 

 sometimes though rarely proved useful. It is called " wiring," 

 and consists in passing a wire or knitting-needle up the nostril, 

 and through the perforated plate of the ethmoid bone into the 

 brain. This is no certain or easy task, for although the passage 

 is straight, it is narrow, and if the needle deviates from its path in 

 a very slight degree it will be stopped by a projection of the 

 frontal bone from above, or the solid portion of the ethmoid bone 

 below. But, assuming that the perforation is effected, its suc- 

 cess must depend on the position of the vesicle ; for if it should 

 happen to be situated too superficially, or too deeply, or in fact 

 anywhere out of the direct line of the needle, it will not be 

 punctured, and, of course, the fluid not being removed, the pres- 

 sure on the brain will continue, while the puncturing is of itself 

 likely to occasion fatal inflammation. 



Other attempts of a mechanical nature have also been made, 

 but with yet more doubtful results, and scarcely more humane in 

 their character. Some farmers have cut off the ears after severely 

 wringing them ; others have dogged the animal, and worried it to 

 exhaustion. The principle of these and similar barbarous and 

 general experiments is the same — to create that violent and con- 

 vulsive struggling in the animal that may perchance rupture the 



* Lectures on the Morbid Anatomy of Serous and Mucous Membranes, 

 by Dr. Hodgkin.— vol. i. p. 185. 



