184 LABOR A TOR Y G U1DE IN PHYSIO LOG Y. 



(a) Add to the mixture above described 2 or 3 c. c. of 

 strained egg albumin; shake vigorously. One ob- 

 serves the same minute subdivision of the particles, 

 but they show no tendency to coalesce on standing; 

 the suspension is "more or less permanent." 



Why do not the particles coalesce? In what 

 respects is this emulsion unlike milk ? 



(b) To 2 c. c. of olive oil add 2 c. c. of sirupy solution 

 of any gum, e. -., gum acacia; shake the mixture 

 thoroughly. An emulsion will be formed. What 

 characteristics has this emulsion in common with 

 emulsion (a) ? 



{c") To 5 c. c. of cotton seed oil containing a little free 

 fatty acid add 10 drops of strong sodium carbonate 

 solution and shake. A good stable emulsion is 

 made in this way. [Long's Chemical Physiology, 

 p. 63.] 



In what way is this emulsion different from those 



which precede ? Which one of the emulsions given 



above is most like the emulsions formed in the small 



intestine ? 



(*/) What matters present in the small intestine tend 



to promote emulsification of fats ? 



(G) The di fusibility of I at s or their derivatives or modifica- 

 tions. 



Fill five dialyzers as follows: 

 (a) Milk. 



() Solution of soap. 

 (e} 10% glycerine. 

 (</) Emulsion (5-a). 

 (e~] Emulsion (5-c). 



Complete the observations on the following day, deter 

 mining what derivations or modifications of fat or oil are 

 diffusible. How may the presence of soap in the dif- 

 fusate be determined ? 



