CAPPED HOCK. 321 



by special desire brought to the College for examination. So re- 

 duced was the diseased hock found, that no more than one-and-a- 

 half inch remained between its measurement round and that of the 

 healthy hock, notwithstanding the time had been when the former 

 exceeded the latter by fourteen inches. 



Case II, however, although similar in its general character, 

 proved, under like treatment, fatal. An* entire cart-horse exhibited 

 his near hock nearly double the size of the off, from the presence of 

 a very large thorough-pin, which had been several times fired. The 

 diseased hock measured twenty-two inches, the sound hock fif- 

 teen. The tumour is low (compared to the one in the former case), 

 and there is accompanying it enormous distention of the capsule of 

 the hock joint. Nevertheless, the subject being given up for ex- 

 periment, the operation was proceeded with. The trocar was in- 

 troduced, and a pint of synovia flowed out. The iodine injection 

 was thrown in, and retained three minutes within the cavity. But 

 the whole of it could not be made to pass out again, in consequence 

 of albuminous matters, discovered to have become effused into the 

 cavity, obstructing the aperture. After the animal had risen, albu- 

 minous synovia flowed from the opening. Pains in the limb and 

 fever followed ; and on this supervened swelling, in particular of 

 the hock joint, which at first fluctuated as though purulent matter 

 was collected, and afterwards emitted a viscous colourless discharge 

 containing pus globules. This went on to ulcerations appearing, 

 and these gave vent, in places, to pseudo-membranous discharges 

 from the joint, having spots upon them indicative of gangrene, 

 which at length was found to have commenced within the joint, 

 under the resorption of the ichor. And of gangrene, as was pre- 

 sumed, the animal at length sank. 



The sacs of the thorough-pin were found inwardly rose-coloured 

 and mammillated, the same as in a suppurative wound. Within 

 them was a yellowish-white soft matter, apparently albumen, coa- 

 gulated by the alcoholic injection. They exhibited gangrenous 

 spots, and had the characteristic foetor. There was found a com- 

 munication between the sacs and the hock joint of above an inch 

 in diameter. The synovial membrane lining the hock joint pre- 

 sented the same aspect as the lining of the sacs. The middle pro- 



VOL. IV. T t 



