214 



PHYSIOLOGICAL CHEMISTRY 



fuse on platinum foil. Cool the residue, transfer it to a test-tube, and dissolve it in 

 water. Add a little dilute sulphuric acid and note the odor of hydrogen sulphide. 

 Hold a piece of filter paper, moistened with a small amount of lead acetate, over 

 the opening of the test-tube and observe the formation of lead sulphide. 



FIG. 64. TAURINE. 



10. Preparation of Glycocoll. Concentrate the alcoholic nitrate from the last 

 experiment (9) until no more alcohol remains. The gJycocoll is present here in the 

 form of an hydrochloride and may be liberated from this combination by the addi- 





FIG. 65. GLYCOCOLL. 



tion of freshly precipitated lead hydroxide or by lead hydroxide solution. Remove 

 the lead by hydrogen sulphide. Filter and decolorize the filtrate by animal char- 

 coal. Filter again, concentrate the filtrate, and set it aside for crystaDization. 

 Glycocoll separates as colorless crystals (Fig. 65). 



