APPENDIX. 405 



regulated to about 37° C, or near a stove. Examine the tube 

 from time to time. The cubes of egg will be seen to be disinte- 

 grating and dissolving. 



A quantity of digested white of egg may be prepared in a 

 cup or bowl and emptied into the inner jar of a dialyzer. After 

 a time the water in the outer jar will give the peptone tests, 

 showing that the digested albumen is diffusible. 



Pancreatic Digestion. 



Procure some of the commercial pancreatic preparations and 

 make an artificial pancreatic juice according to the .directions 

 furnished with each preparation. Test the reaction with litmus 

 paper. It will be found to be alkaline. ■ Try the effect of the 

 artificial preparation on starchy and on albuminous substances 

 in the manner given above for each. The pancreatic juice will 

 be found to change starch to grape-sugar and proteids to pep- 

 tones. Try its effect also on oil by adding a few drops of olive 

 oil to some pancreatic juice in a test-tube. At first the oil will 

 float on the surface of the liquid. Shake the tube vigorously 

 to mix the two substances. The oil will be broken up into fine 

 droplets, giving the contents of the tube a milky appearance. 

 On standing for a time it will be seen that the oil does not sep- 

 arate from the digestive juice and collect at the surface as it 

 would if shaken up with water, but the two fluids remain inti- 

 mately mixed, forming an emulsion. Under a microscope ex- 

 amine a drop of the emulsion. It will be seen to consist of 

 innumerable fine drops of oil, which remain separate from one 

 another. If oil be shaken up with saliva or with artificial gas- 

 tric juice no emulsion will be formed, the oil soon separating. 



CHAPTER XII. 



Directions for obtaining and studying blood -corpuscles aro 

 given in the notes on Chapter V. Suflacient blood to show the 

 phenomena of clotting may be obtained by chloroforming a rab- 

 bit or a fowl, cutting one of the veins in the neck, and catching 

 the blood in small tumblers or beakers. 



