2l8 PHYSIOLOGICAL CHEMISTRY 



solution of sodium carbonate for every liter of water previously added and 

 inoculate with some putrescent material (pancreas or feces). 1 Mix the putre- 

 faction mixture very thoroughly by shaking and insert a cork furnished with a 

 glass tube to which is attached a wash bottle containing a 3 per cent solution of 

 mercuric cyanide. 2 This device is for the purpose of collecting the methyl 

 mercaptan, a gas formed during the process of putrefaction. It also serves to 

 diminish the odor arising from the putrefying material. Place the putrefaction 

 mixture at 4oC. for two or three weeks and at the end of that time make a sepa- 

 ration of the products of putrefaction according to the f ollowing directions : 



Subject the mixture to distillation until the distillate and residue are approxi- 

 mately equal in volume. 



PART I 

 MANIPULATION OF THE DISTILLATE 



Acidify with hydrochloric acid and extract with ether. 



I 



I ~| 



Ether Extract No. i. Residue No. i. 



Add an equal volume of water, make alka- Allow the ether to volatilize. Evapo- 



line with potassium hydroxide, and shake rate and detect ammonium chloride 



thoroughly. crystals (Fig. 66, page 219). 



I I 



Ether Extract No. 2. Alkaline Solution No. i. 



Evaporate spontaneously. Indole and Acidify with hydrochloric acid, add 



skatole remain. Try proper reactions (see sodium carbonate, and extract with 

 pages 221 and 222). ether. 



I I 



Ether Extract No. 3. Alkaline Solution No. 2. 



Evaporate. Detect phenol and cresott Acidify with hydrochloric acid, and 



(paracresole). See page 222. extract with ether. 



Ether Extract No. 4. Final Residue. 



Evaporate. Volatile fatty acids remain. (Discard.) 



DETAILED DIRECTIONS FOR MAKING THE SEPARATIONS 

 INDICATED IN THE SCHEME 



Preliminary Ether Extraction. This extraction may be conveniently conducted 

 in a separatory funnel. Mix the fluids for extraction in the ratio of two volumes 

 of ether to three volumes of the distillate. Shake very thoroughly for a few mo- 

 ments, then jlraw off the extracted fluid and add a new portion of the distillate. 

 Repeat the process until the entire distillate has been extracted. Add a small 

 amount of fresh ether at each extraction to replace that dissolved by the water in 

 the preceding extraction. 



1 Putrefying protein may be prepared by treating 10 grams of finely ground lean meat 

 with roo c.c. of water and 2 c.c. of a saturated solution of sodium carbonate and keeping 

 the mixture at 4oC. for 24 hours. 



* Concentrated sulphuric acid containing a small amount of isatin may be used as a 

 substitute for mercuric cyanide. When this modification is employed it is necessary to 

 use calcium chloride tubes to exclude moisture from the isatin solution. 



