NATURE AND HISTORY. 373 



That the urine resembling oil was albuminous there seems 

 little doubt ; that the portion resembling porter was mingled 

 with blood, subsequently and slowly trickling from the kidney, 

 appears probable ; but why this should suddenly change and 

 become like whey I must confess I do not pretend to offer an 

 explanation,' 



Thus it is perfectly evident that this disturbed state of the 

 process of assimilation, culminating in the conditions of 

 muscular spasm and altered urinary secretion, was well enough 

 Imown to Mr. Percival, whatever interpretation he might give 

 to these phenomena ; for no one reading the notice we have 

 transcribed, and at all conversant with the affection, can have 

 any doubt that the case reported is one of what is now desig- 

 nated azotized urine. In the record of this reported case, 

 amongst other salient features, it may be observed that parti- 

 cular stress is laid upon the suddenness which marked the 

 change of colour in the urine in a very short period. 



At one time, and with some observers, this condition was 

 curiously enough believed to be confined to mares, or at least 

 in them to be much more frequently encountered than in 

 staUions or geldings. This, however, is in a great measure dis- 

 proved, as neither sex, breed, nor age, provided the animals 

 have reached maturity and are stabled, seems to grant immunity 

 from an attack. I have observed that it is more apt to seize 

 upon animals rather handsome, well shaped, and good thrivers, 

 than others differently constituted ; that it does not, or very 

 rarely, attack horses roaming at large in the fields, Avhether 

 young or old ; also that in all cases it is more apt to occur 

 under favourable conditions succeeding a period of rather 

 smart or active work followed by enforced idleness. 



b. Causation. — There seems sufticient and readily enough 

 obtainable evidence that the true and ultimate causes of 

 this interesting but serious disorder are dietetic ; that the 

 symptoms exhibited are the result of the passage into the 

 system of an abnormal amount of albuminous or nitro- 

 genous material; and that to certain changes which these 

 albuminoids undergo when present in excess, and when 

 brought into contact with other materials and under the 

 influence of certain surrounding agencies, must be attributed 

 the whole of the complex phenomena which characterize or 



