Litter, 223 



comes no doubt in a considerable degree vitiated. But, it must be 

 recollected that dogs (except in extreme cases) instinctively avoid 

 contaminating their beds, with their urine or foeces, which would be 

 the means of exciting the fermentative process in the straw, and 

 thus, as little or no putrefactive fermentation goes on in their beds 

 so, little or no Volatile Alkali will be generated from this source. If 

 any one will take the trouble of comparing the pungent effects 

 which arc produced upon the eyes and nose, by the air of stables^ 

 with the merely nauseous smell produced by that of kennels, he will 

 have no hesitation in admitting the validity of these remarks. Now, 

 the facts that have been already adduced on the authority of Doctor 

 Egan, may serve to convince us that the urine alone, would be capa- 

 ble of dift^using an abundant quantity of Volatile Alkali in the air of. 

 stables, independently of any other source. Not having had an op- 

 portunity of making a set of experim.ents on the urine of different, 

 animals, which would enable me to speak possitively on the subject, I 

 cannot venture to assert that the urine of the Horse contains more urea 

 or gelatine than that of other animals, but I think we may reasonably 

 presume one or other of these circumstances to be the case. For, 

 Fourcroy and Vauquelin have ascertained that the difference which* 

 exists in different urines, as to their susceptibility of the putrefactive 

 process, depends on the relative quantity of urea which they contain, 

 and has been proved that the rapid putrefaction of urine is owing 

 to the action of gelatine on that singular substance. 



And further, we know from the experiments of these celebrated 

 chemists, that urea is the great source of the Volatile Alkali, which 

 is generated during the putrefaction of urine, inasmuch, as Zgo- 

 parts of urea were found to yield by distillation 200 parts of carbo^ 



