200 Jir. 



tliem out, which is veiy similai' in its effects upon the organs of 

 smell and eight to the application of hartshorn to the nostrils. Now, 

 this violent impression made upon the nerves of the nose by the at- 

 mosphere of the stable, is, in fact, produced by the very same salt 

 ^vhich gives pungency to the fluid called hartshorn, and v'hich is 

 perpetually, though imperceptibly, diffusing itself through the at- 

 inosphere of even the best-ventilaled stables. Fcr we are not to 

 suppose that the aci of disturbing the litter is tlie sole means of 

 diffasing the Volatile Alkali, much less of generating it in the atmos- 

 phere of the stable ; inasmuch as the production of this peculiar 

 salt is the inevitable consequence of the putrefactive fermentation 

 of the litter, which in these countries is composed of such materials 

 as readily undergo this chemical change, and more especially when 

 the urine and foeces of the animal are mixed with it. But, the im- 

 mense quantity of Ammonia or Hartshorn which is d.lTused in the 

 atmosphere of stables is produced in a space of time which must ap- 

 pear inconceivably small, even to those who have made chemistry 

 ?in object of their study, provided no other source for its production 

 besides the fermentation of the litter could be discovered. For, if 

 we suddenly enter the cleanest and best-ventilated stable (especially 

 if we do so on quitting the lYesh external air) we shall immediately 

 be sensible of the presence of somewhat in the atmosphere similar 

 in its effects to hartshorn, and this too at all times, and by no mean* 

 at the particular period of the removal of the litter. This cinum- 

 .vlancel had frequently been struck with, without being sble to ac- 

 count for the fact iw a manner that wns sr-fficiently satisfactory to my 

 own mind. For though in tlie course of very frequent corsidcrslion.'? 

 '■'f this subject 1 made 'cycij rcasonn]>le eIi<;wnn<^o for the lairjwri 



