GLYCOGEN IN THE LIVER. 67 



parapeptones. The acid of the gastric juice splits up the 

 bile-salts, so that the bile acids are also thrown down. 



(/.) Action on Syntonin. Prepare syiitonin in solution 

 (Lesson I., 7,/), and add a few drops of bile or bile-salts. It 

 causes a curdling of the whole mass. Be careful not to add 

 too much bile. In (e.) and (/.) it is better to add the bile- 

 salts, because the free hydrochloric acid gives a precipitate 

 with bile. 



LESSON X. 

 GLYCOGEN IN THE LIVER. 



1. Preparation. 



(a.) Boil some water slightly acidulated with acetic acid, 

 and keep it boiling. Feed a rat, and three or four hours 

 thereafter decapitate it. Rapidly open the abdomen, remove 

 the liver, cut one half of it in pieces, and throw it into the 

 boiling acidulated water. Lay the other half aside, keeping 

 it moist in a warm place for some hours. After boiling the 

 first portion for a time, pound it in a mortar with sand, 

 and boil again. Filter while hot. The filtrate is milky 

 or opalescent, and is a watery solution of glycogen. The 

 acetic acid coagulates the proteids, while the boiling water 

 destroys a ferment in the liver, which would convert the 

 glycogen into grape-sugar. 



(b.) Feed a rabbit on carrots, and after from two to three 

 hours decapitate it. Open the abdomen, tear out the liver, 

 cut it rapidly in pieces, and take one half laying the 

 other half aside as in (a.) throw it into boiling water, boil it, 

 and afterwards pound it in a mortar and boil again. Filter 

 while hot, and observe the opalescent filtrate, which is a 

 solution of glycogen and proteids. The filtrate should flow 

 into a cooled beaker, placed in a mixture of ice and salt. 

 Precipitate the proteids by adding alternately hydrochloric 

 acid and potassio-mercuric iodide, until all the proteids are 

 precipitated. Filter off the proteids, and the beautiful opal- 



