PUTREFACTION PRODUCTS 217 



PART II 

 MANIPULATION OF THE RESIDUE 



Evaporate, filter, and extract with ether. 



Ether Extract. Aqueous Solution. 



Evaporate, extract the residue with Evaporate until crystals begin to 



warm water, and filter. form. Stand in a cold place until 



crystallization is complete. Filter. 



Crystalline Deposit. Filtrate No. i. 



Consists of a mixture of Contains protease, peptone, 



leucine and tyrosine crystals aromatic acids, and tryptophane. 



(Figs. 25, 28 and 139, pages 

 76, 80 and 463.) 



Filtrate No. 2. Residue. 



Contains oxyacids and Contains non-volatile 



skatole-carbonic acid. fatty acids. 



DETAILED DIRECTIONS FOR MAKING THE 



SEPARATIONS INDICATED IN 



THE SCHEME 



Preliminary Ether Extraction. This extraction may be conducted in a separately 

 funnel. In order to make a satisfactory extraction the mixture should be shaken 

 thoroughly. Separate the ethereal solution from the aqueous portion and treat 

 them according to the directions given on page 215. 



Ether Extract. Evaporate this solution on a safety water-bath until the ether 

 has been entirely removed. Extract the residue with warm water and filter. 



Aqueous Solution. Evaporate this solution until crystallization begins. Stand 

 the solution in a cold place until no more crystals form. This crystalline mass con- 

 sists of impure leucine and tyrosine. Filter off the crystals. 



Crystalline Deposit. Examine the crystals under the microscope and compare 

 them with those reproduced in Figs. 25, 28, and 139, pages 76, 80, and 463. Do the 

 forms of the crystals of leucine and tyrosine resemble those previously examined? 

 Make a separation of the leucine and tyrosine and apply typical tests according to 

 directions given on pages 85 and 86. 



Filtrate No. i. Make a test for tryptophane with bromine water (see page 189), 

 and also with the Hopkins-Cole reagent (see page 98). Use the remainder of the 

 nitrate for the separation of proteoses and peptones. Make the separation ac- 

 cording to the directions given on page 120. 



Filtrate No. 2. This solution contains para-oxyphenylacetic acid, para-oxy- 

 phenylpropionic acid and skatole-carbonic acid. Prove the presence of these 

 bodies by appropriate tests. Tests for oxyacids and skatole-carbonic acid are 

 given on page 220. 



