EXAMINATION OF BILE. 89 



of alcohol (or mix with it), after twenty-four hours filter 

 off the taurine which has separated, wash with alcohol 

 and recrystallize it from hot water,' using some bone- 

 black to decolorize. Taurine (amino-ethyl sulphonic acid), 

 CH 2 NH 2 



, crystallizes in large, transparent, glittering prisms, 

 CH 2 S0 3 H 



which are readily soluble in hot water, more difficultly in 

 cold, and insoluble in absolute alcohol. 



1. Heat a few crystals on platinum-foil: the taurine 

 melts, turns brown and carbonizes on heating more strongly, 

 developing a suffocating odor (sulphurous acid [and sulphuric 

 acid ?]).' 



2. Powder a few crystals, mix with several times their 

 volume of dry sodium carbonate, and fuse on platinum-foil. 

 After cooling, dissolve the fused mass in water, put it into 

 a test-tube, and add some dilute sulphuric acid: odor of 

 hydrogen sulphide. Moisten a strip of filter-paper with a 

 solution of lead acetate and remove the excess of the solu- 

 tion by pressing between filter-paper. When held over the 

 opening of the test-tube this paper turns brown or black 

 owing to the formation of lead sulphide. 



