1^4 On the Benzoic Acid in the Urine of Horses* 



action: of its. original elements. I therefore first undertook 

 to examine the usual food of these animals, hay and oats. 

 Hay contains a large quantity of a grass with a very agreea- 

 ble smell, the anlhoxanthi/m odnratum Linn. Fourcroy and. 

 Vauquelin had already suspected that this plant contained 

 benzoic acid : this and other considerations confirmed me 

 in the same opinion, and gave me reason to hope that I 

 should find in it the source of the benzoic acid. 



Experiment I. 



A quantify of this grass was put into a very dry retort* 

 connected with a balneum marine, and, being placed in a 

 Rand-bath, uag exposed to such a degree of heat that the 

 benzoic acid contained in it could be sublimated ; but after 

 the fire had been maintained a considerable time, no traces' 

 of it were observed. 



Experiment If. 

 One part of this grass was boiled with twelve parts ofi 

 lime water. The decoction had a very agreeable smell : it 

 was then brought to the consistence of syrup ; and muriatic 

 acid being" added, a precipitate was produced, which how- 

 ever on being tried exhibited none of the properties of ben- 

 zoic acid. 



Experiment III. •> 



An extract prepared from a quantity of this grass had a 

 verv strons: smell, very much like that of the trijolium me- 

 f'rlnhim. This extract, being digested some time in spirit 

 of wine, had a verv agreeable smell. It was then exposed 

 to a slow evaporation, after which it exhibited no percepti- 

 ble traces of benzoic acid. 



It results from these experiments, made in different ways, 

 that the benzoic acid does not originate from the hav. 



It now remained for nie to examine oats : I therefore sub-' 

 lected it to the same process, but could diseo\Tr no signs 

 C>f l>enzoic acid. 



* Being confident that I had pursued the riijht method in 

 tf^ese experiments, I thought mvself authorized to conclude 

 with certainty that I must look for the origin of the benzoic 

 acid in the animal body itself. The following experiments 

 will serve as a confinnation of this idea : 

 ■ ! examined the urine of a horse which had been fed on 

 ihc same food as that given to those the urine of which 

 produced a Irrgc quantity of benzoic acid. This urine, 

 however, produced verv little. Had the benzoic acid been 

 indebted for its origin to the food, the urine of horses foci 

 •• *" on 



