82 THE HORSE AND ITS DISEASES. 



qualities rendered latent, so long as they remain in the 

 stomach, or in the lacteals, and even in the blood ; but 

 as soon as any separation takes place within the kidneys, 

 these substances recover their qualities, hence, canthar- 

 ides received through this medium, or by the surface of 

 the skin, produces no sensible effect on the blood vessels ; 

 but as soon as they have been seperated from it by these 

 organs, they then produce the most sensible effect — infla- 

 ming the kidneys, literius, and more particularly the 

 neck of the bladder, producing strangury. Nitre and 

 resin produce diarrhetic effect, neither being active while 

 existing within the blood vessels, but as soon as circu- 

 lated through the kidneys, they produce a high degree 

 of stimulus to those organs, whereby they seperate much 

 more of the watery parts of the blood than usual. From 

 the great vascularity of the kidneys, they are subject to 

 inflammation, to calculus concretions, and diabetes ; and 

 as their ofHce is so important, so under inflammation, the 

 efi'ects produced are as serious and destructive as would 

 occur in other parts of twenty times their magnitude. 

 The most frequent ailment, however, to which they are 

 exposed, is that of being bruised by the action of the 

 lumber muscles, in violent exercise, which bruises 

 produce a lesion of their fine vessels, and hence it is so 

 common for horses who have been hard ridden to make 

 bloodv urine. 



The Ureters. 



The urine having been separated from the blood, and 

 passed into the pelvis of each kidney, is then carried off 

 by means of two muscular tubes, one to each, called the 

 ureter. These canals pass out of the posterior part of 

 each sinew, and are continued backwards, not in a 

 straight direction ; being continued towards the bladder, 

 they gradually approach each other, and are crossed upon 

 by the spermatic rope, and finally inserted at some 

 distance from each other within the bladder. 



