290 Disease amowj Lanchs. 



rend them, their mucous lining membrane being so structurally 

 disinteg-rated as to separate at the slightest touch. The pallid 

 liver is solt, pulpy, and of large size from congestion ; its substance 

 can be broken down by the finger with the greatest ease. In the 

 stomach is a quantity of semi-fluid ingesta, whilst the intestines 

 contain a large quantity of green-coloured fluid, mixed with par- 

 ticles of undigested food. The kidneys are found congested, but 

 surrounded by a {|uantity of fat ; the omentum also contains a 

 fair amount of fat. The coats of the bladder are extremely thin ; 

 indeed so attenuated do they become, that in several instances 

 rupture has taken place either before death or very soon after : 

 this, as well as the biliary cyst, are usually found full of abnor- 

 mally light-coloured secretion. 



Considering the age and breed of the animals, the season of 

 the year, the general juanagement of the flocks, the symptoms 

 presented, and the post-mortem examination, the practical con- 

 clusion at which I arrived was, that the malady chiefly depends 

 on a defect in the nitrogenous element of nutrition, arising either 

 Irom the insufhciency of supply or the incapacity of the young 

 animal to assimilate the flesh-forming elements in the condition 

 in which they are given. In order to be clearly understood, 1 

 must make a few general remarks on Food. 



Food may be theoretically regarded as consisting of two prin- 

 ciples or elements having a two-fold operation to perform. The 

 one, the hydro-carbonaceous or heat-forming material, of which 

 nitrogen forms no part, is necessary to maintain, by its combina- 

 tion with oxygen in the system, the natural standard of animal 

 heat: this principle, if supplied in excess, is stored up in the 

 form of fat, to be employed in the generation of animal heat if 

 the supply from external sources should at any future time fail. 

 The other, the nitrogenous or tissue-forming principle, is required 

 to build up the growing organism as its development advances, 

 and also to replace tissues disintegrated by the natural molecular 

 waste oi the body or the results of extraordinary exertion. The 

 operation of this principle is sometimes distinctively called 

 " nourishment." If the supply of this principle exceeds the 

 immediate requirements of the system it is not stored up for 

 future use (except the small amount available for increasing the 

 richness of the blood), but passes out with the excretions and is 

 the chief source of ammonia in them. On the proper balance 

 of these two elements in the food, the health and well-being of 

 every animal depends. This balance, however, must be variously 

 adjusted to suit it, not only to animals of different ages, but also 

 of different breeds. We have reason to think that a greater pro- 

 portion of the nitrogenous principle is required in the suckling 

 than in the adult, and (from the enfeebling influence of a delicate 



