On the Benzoic Acid In the Urine of Hor sex. 153 



on the same fodder must have produced a hke quantity of 

 benzoic acid ; which, after repeated experiments, was not 

 found to be the case. A question now arises. In what state 

 of the animal is this acid formed in the body ? in the sound 

 or diseased state ? I flatter myself that I am able to answer 

 this question, as I had an opportunity of ascertaining, with 

 great correctness, the state of the horses the urine ot which 

 1 exanuned. The result was, that a horse whose urine gave 

 a great deal of benzole acid had been long diseased, and 

 that the horse whose urine gave very little or no benzoic 

 acid was perfectly sound. But wdiat is the disease during 

 which benzole acid is produced ? This question is the most 

 important and most difficult. The determination of it is of 

 great importance to the physiologist, as it calls his attention 

 towards the cause of the formation of this acid ; and is 

 worthy the notice of the chemiat also, as it holds forth an in- 

 dVictment for him to examine under what circumstances he 

 can derive utilitv from this product. 



For this purpose a long series of experiments would be 

 necessary ; but these experiments can be made only by those 

 who have the care of diseased horses, that is to say, in a 

 veterinary college. Hitherto I have had no opportunity of 

 undertaking this labour ; I shall therefore content myself 

 with collecting into one point of view the facts which seem 

 to result from these experiments. 



I. The urine of horses is so very different, that nothing 

 certain can be determined in regard to the quantity of ben- 

 zoic acid which it contains. 



II. The following five cases, however, occur in this re- 

 spect in the preceding experiments : — 1st, There are some 

 kinds of urine in which at first a large quantity of benzoic 

 acid is found neutralized with soda : 2d, In u hich a very 

 small quantity of bcnzoate of soda exists : 3d, In which 

 the same quantity is found in the free state : 4th, In which 

 none is to be found : and, .5tb, In which only a large quan- 

 titv of pure calcareous earth is observed. 



III. 'i'he diH'erence of urine in regard to the benzoic acid 

 it contains, does not arise from the food of the horses, but 

 from the various states in which these animals may be by 

 derangements in their functions. 



I\'. The state of the animal in which a quantity of ben- 

 zoic acid is produced, is worthy of further examination. 



Remark Irj M. Sc/icrer. 

 It Is always very difficult in researches of this kind to 

 .obtain ceitaiu jc^ults, I think there is great reason to be- 

 lieve 



