INTERNAL SECRETIONS. 



fine sand, return to the capsule, and boil again for a short time to 

 make certain that the diastatic power of the liver has been de- 

 stroyed. Add ten volumes of water slightly acidulated with acetic 

 acid. Strain through muslin. To remove the proteids, concen- 

 trate the liquid to a third its volume and add alternate drops of 

 HCl and potassium mercuric iodid until precipitation ceases. 

 Filter off a little of the liquid and test the filtrate for proteids. If 

 there are none present, strain all of the liquid through muslin and 

 filter through paper. To the filtrate add two volumes of alcohol, 

 stirring well. Allow the precipitate, glycogen, to settle, decant off 

 the supernatant liquid, filter the residue, and wash with dilute al- 

 cohol. Transfer the residue to a beaker, cover with absolute alco- 

 hol, and set aside for an hour. Remove the alcohol and dry the 

 residue between folds of filter paper. 



To some of the glycogen thus prepared add 25 c.c. of water and 

 warm gently. A solution is formed. Compare the appearance of 

 this solution with that of soluble starch. 



Test a little of the glycogen solution with iodine and KI. Note 

 the color reaction. Does it disappear upon heating ? If so, does 

 it reappear upon cooling ? 



Test some of the solution of glycogen with Fehling's reagent. 

 Is there any reduction of the copper salt brought about ? 



To a little of the glycogen solution add some saliva. After a few 

 minutes test with Fehling's reagent for reducing sugar. 



II. PANCREATIC DIABETES. 



Effect of Removal of the Pancreas on Carbohydrate Metabolism. 

 Collect the urine of a medium-sized dog and test for reducing sugar 

 with Fehling's solution. In all probability none will be found. 

 Starve the dog for twelve hours. Inject subcutanrously 0.12 gram 

 of morphine sulphate. Place dog, back down, on the operating- 

 board and continue the anaesthesia with ether. Prepare sterile 

 medium and heavy silk suture material. Sterilize a number of 

 absorbent cotton pads in physiological salt solution. Sterilize 

 instruments by steam or by boiling. 



