156 COMBUSTIBLE ACIDS. 



of his inaugural dissertation. Since that time, 

 some important additions have been made to 

 our knowledge of its properties and constitution 

 by Dr. Prout. 



The uric acid which I made use of in the fol- 

 lowing experiments was obtained from the ex- 

 crements of the boa constrictor. This serpent 

 voided its excrements about once in the month : 

 the matter was white and solid, and in appear- 

 ance very similar to the album Graecutn voided 

 by dogs. A slight examination of it satisfied 

 me that it consisted almost entirely of uric acid. 

 It was digested in caustic potash ley, by which 

 the greatest part of it (indeed almost the whole) 

 was dissolved. The solution was drawn off clear 

 from the undissolved sediment, and mixed with 

 a sufficient quantity of very pure acetic acid, to 

 saturate the whole of the potash. A copious 

 white precipitate fell, which was collected on 

 the filter, and thoroughly washed by the affusion 

 of a great quantity of water. It was then dried 

 in a gentle heat, and considered as pure uric 

 acid. 

 Properties 1. Uric acid thus prepared was sometimes in 



of uric (t 



acid. the state or an impalpable powder sometimes 

 in small four-sided prisms, having a good deal of 

 lustre. I was not able to procure these crystals 

 at pleasure ; but succeeded most frequently 

 when the precipitate was separated by the filter 

 from the supernatant liquid, immediately after 



