CAUSATION. 375 



me that such is not imperative ; that animals may become 

 ati'ected in this manner when remaining in the stable, provided 

 the extra siippl^^ of nutriment of this particular kind is kept 

 up. It seems quite sufficient for the development of this 

 disease that the materials supplied be in full quantity, of rich 

 character, particularly of a highly albuminous or nitrogenous 

 nature, and the horses kept from Avork or exercise. 



The system seems incapable of utilizing this extra amount 

 of nutrition received, either as a reserve upon which it might 

 at some future time draw, or as jDabulum to be consumed in 

 the performance of the different functions of animal life. This 

 material enters the system and circulation, and at some step or 

 steps in the complex process of assimilation or manufacture of 

 received material into blood, or pabulum lit for appropriation 

 by the various tissues, it undergoes certain changes ; the result- 

 ing products, instead of being either healthful or innocuous, 

 prove actually deleterious, poisoning the tissues when it ought 

 otherwise to yield health and power. 



The great characteristic features of the disease, the ura^mic 

 condition of the urine, the exaltation and ultimate loss of 

 function of particular parts of the voluntary muscular system, 

 and the extensive disturbance of the nervous system, are all 

 related more or less directly to the superabundant supply of 

 a jDarticular nutritive material, and to the disturbance or per- 

 version of function, not very well understood, at some jjoints 

 of the assimilator}^ process. The unemic state of the urine is 

 probably the simple result of the pathological condition of the 

 blood, and accounted for on the recognised physiological or 

 functional power of the kidneys to separate, as urea chiefly, 

 certain chemically formed materials, here probably imperfectly 

 changed albuminoids, and to pass them off in the urine. 



The musculo-nervous phenomena may owe their origin either 

 to directly perverted and disturbed nutrition of both muscular 

 and nerve tissue, or to perturbed and diseased nerve-power 

 operating through reflex action. 



When developed in lighter animals, and those employed for 

 fast work, the same general causes seem to be in operation 

 which we have already indicated as observed in agricultural 

 horses. 



It has been noticed by some writers as being more likely to 



