CHAP. II.] ABSCESS AND TUMOUR. 305 



one kidney is affected at a time, or one ureter ; 

 that the calculi found in either of these is invariably 

 of the hardest kind, whilst those of the bladder are 

 softer, and those of the intestines softer still, or 

 little more than concrete earth. Lastly, that none 

 of those horses we have found troubled with either 

 kind of calculous disorder suffered under a second 

 kind at one and the same time. 



CHAPTER II. 



EXTERNAL DISEASES. 



Abscess and Tumour; Fistula, Sfc. 



Swelling, with inflammation of the solids, the 

 glands, or simply pustules on the skin, are all 

 tumours, and have been divided into eight classes, 

 but when lying deep, are termed abscess, to denote 

 recession from the sight. Poll evil, fistula in the 

 withers, quittor, warbles, range under this head ; 

 as do farcy, strangles, grease, and perhaps glan- 

 ders, owe their origin to the same cause, viz. an ill 

 state of the blood, its vessels, and the means of 

 carrying on the circulation, as happens to all ani- 

 mals that gorge too much, or are fed badly. A few 

 general observations on the remote causes hereof 



