222 Litter. 



proofs that the Volatile Alkali which is generated in litter, is at least 

 capable of aggravating the disease called moon-blindness^ and the 

 more we consider the phcenomena of this disorder^ the more we shall 

 be justified^ I think^ in concluding- that the use of litter is the grand 

 cause of this singular affection of the eye. For, though it must be 

 admitted that some inexplicable peculiarity of structure does cer- 

 tainly exist in the outer coat of the eye of the Horse, which lays him 

 more open to derangements in its functionSj than any other animal 

 which we domesticate, yet, there can be no question that this primeval 

 suceptibility of disease, is called into action, chiefly by means of the 

 Volatile Alkali which has been proved to exist so abundantly in the 

 air of stables. To this notion, however, of mine, of the hurtfulness 

 of Volatile Alkali, which I have long been endeavouring to obtain 

 converts to, I have heard it objected, that dogs which are crowded to- 

 gether in kennels, and which must, consequently, be subjected to the 

 influence of a fouler atmosphere than that of stables, are not pecu- 

 liarly subject to disorders of the eyes, and rarely become blind until 

 the arrival of old age. 



But, if this argument be closely investigated it will be found 

 rather tostrenghten, than to invalidate, that which I am endeavouring 

 to support. For, we must not suppose that the putrefactive fermen- 

 tation (the parent of Volatile Alkali) goes on in kennels, notwithstand- 

 ing the nauseousness of their stench, in any thing like the degree 

 that it does in stables. We must distinguish in fact between the effects 

 of odour and those of the putrefactive process. The smell of kennels, 

 it is true, is often loathsome to a great degree, from a variety -of causes, 

 and chiefly, perhaps, from a concentration of the effluviae which ex- 

 bale from the sking of the dogs, by which means the atmosphere be-. 



