48 



celain capsule, adding a drop or 'two of a solution- of cane 

 sugar and then a few drops of strong sulphuric acid. 



164. Gmelin's Test for Bile Pigments. Ox gall does not 

 yield this test as readily as that from the omnivora or carni- 

 vora. To a small quantity of bile, in a test-tube, add, drop 

 by drop, nitric acid, yellow with nitrous acid, (if the acid is 

 clear, add a single crystal of cane sugar, warm, and the acid 

 becomes yellow from the development of a small amount of 

 nitrous acid), shaking after each drop ; the yellowish green 

 color becomes first a dark green, then blue, then violet, then 

 red, and finally a dirty yellow. The blue and violet colors are 

 less obvious than the rest. 



Repeat the test in the following way : place a drop of bile 

 in a porcelain evaporating dish, and place a drop of yellow 

 nitric acid so that it runs into the drop of bile ; where the fluids 

 mingle, zones of color, green, blue, violet, red and yellow, from 

 the bile to the acid, are seen. 



165. Surface Tension Test. (Hay). In a test tube con- 

 taining some dilute (1-2) bile, sprinkle some powdered sulphur. 

 Repeat the experiment upon a test tube containing ordinary 

 water. Compare the two and note in which the sulphur sinks 

 the most readily. 



166. Place some diluted bile in a test tube, incline the 

 tube and add cautiously 2-3 cc. of a dilute tincture of iodine 

 so that it forms a layer. In a short time a bright green ring 

 forms at the zone of contact. After the ingestion of antipyrin, 

 the urine will give a similar green ring with iodine. 



167. Acidulate some dilute bile with acetic acid, add a 

 few cc. of chloroform and shake. The chloroform dissolves the 

 bilirubin (not biliverdiu) and is colored yellow. 



168. Add a little bile to some starch mucilage as in sali- 

 vary digestion. Test for any reducing sugar. 



169. To 5 cc. of undiluted bile add an equal volume of 

 water and some alcohol, to precipitate the mucin. Filter and 

 divide the filtrate into two portions ; to one portion add some 

 hydrochloric acid which causes a precipitation of glycocholic 

 acid ; to the other portion add a little of a 1% solution of neu- 

 lead acetate which throws down lead glyeocholate. Remove 

 this by filtration, and to the filtrate add a little 1% solution 

 of basic lead acetate, which gives a further precipitation of 

 lead taurocholate. [Long.] 



