72 BILE. 



4. Purified bile dissolved in absolute alcohol, and 

 mixed with an equal bulk of ether, forms an immediate 

 deposit. Place this mixture in freezing air, or into 

 a freezing mixture, and after twenty-four hours observe 

 that crystals are formed and the liquid is clear. These 

 crystals are a mixture of glykocholate and tauro-cholate 

 of sodium. Evaporate the ether and observe the crys- 

 tals of cholesterine and fats. 



5. Add to a watery solution of purified bile neutral 

 lead acetate as long as a precipitate is produced. The 

 white plaster -like deposit is glykocholate of lead. 



6. Add to the filtrate, from the glykocholate, a 

 solution of basic lead acetate as long as a precipitate is 

 produced. The latter consists of taurocholate of lead. 



7. Filter the liquid and treat with hydrothion ; filter 

 again, evaporate to dryness and burn the residue to a 

 white ash. Observe that it consists principally of 

 sodium carbonate, little potassium carbonate, some 

 chlorides, and earthy salts in small quantity. 



8. Boil a quantity of purified bile dissolved in water 

 with excess of caustic baryta for several hours. Sepa- 

 rate solution from insoluble salt and crystals which 

 form on cooling, and remove excess of baryta by car- 

 bonic acid. Add to the concentrated solution platinic 

 chloride, and observe and examine crystalline precipi- 

 tate of choline -platinum chloride. 



9. Remove from this solution the excess of platinum 

 by hydrothion, evaporate to small bulk and add much 

 absolute alcohol. Let stand for twenty-four hours, then 

 isolate crystals, recrystallise from hot water, and study 

 the pure taurine. 



