PUTREFACTION PRODUCTS. 



167 



pressure within the vessel. The volatile fatty acids are dissolved 

 by the ether (Ether Extract No. 4). 



Ether Extract No. 3. Evaporate this ethereal solution on a 

 water-bath. The oily residue contains phenol and cresol. The 

 cresol is present for the most part as paracresol. Add some water 

 to the oily residue and heat it in a flask. Cool and prove the pres- 

 ence of phenol and cresol. For tests for these bodies see page 170. 



Ether Extract No. 4. Evaporate on a water-bath. The volatile 

 fatty acids remain in the residue. 



PART II. 



MANIPULATION OF THE RESIDUE. 



Evaporate, filter and extract with ether. 



L 



Ether Extract. 



Evaporate, extract the residue 

 with warm water and filter. 



Aqueous Solution. 

 Evaporate, until crystals begin to 

 from. Stand in a cold place until 

 crystallization is complete. Filter. 



Crystalline Deposit. 

 Consists of a mixture 

 of leucine and tyrosinc 

 crystals. (Figs. 23, 26 

 and 104, pages 72, 76 and 

 350.) 



Filtrate No. i. 

 Contains protease, pep- 

 tone, aromatic acids and 

 tryptophane. 



Filtrate No. 2. 

 Contains oxyacids and 

 skatole-carbonlc acid. 



Residue. 



Contains non-volatile 

 fatty acids. 





DETAILED DIRECTIONS FOR MAKING THE 

 SEPARATIONS INDICATED IN 

 THE SCHEME. 



Preliminary Ether Extraction. This extraction may be con- 

 ducted in a separatory funnel. In order to make a satisfactory ex- 

 traction the mixture should be shaken very thoroughly. Separate 

 the ethereal solution from the aqueous portion and treat them ac- 

 cording to the directions given on p. 168. 



