5 6 



COMPOSITION OF THE BODY 



5. Amount of fermentable sugar in the solution. Fill an Ein- 

 horn's saccharimeter (See Fig. 82) with the solution after a little 



compressed yeast has been shaken up 

 in it, taking care to fill the graduated 

 limb of the instrument. The yeast must 

 be active and free from fermentable car- 

 bohydrates. Set the instrument in a 

 warm place. After fermentation has 



FIG. 82. Einhorn's fermen- 

 tation saccharimeter. 



ceased the amount of CO 2 evolved is 

 read off on the graduated scale. The 

 figures will indicate directly the amount 

 of fermentable sugar in the solution. A 

 control test should be made by taking a 

 second instrument of the same kind and 

 introducing water and some of the same 

 yeast. The amount of carbon dioxide 

 evolved in this way should be subtracted from the quantity in the 

 other instrument. 



6. Crystals of cane-sugar. Add r&~- / 



strontia-water to the solution in con- L/j y 



siderable quantity, and after filter- x/ i/ 



ing, evaporate the filtrate until a 

 yellow amorphous precipitate begins 

 to separate out. After it has stood 

 for some time collect the precipitate 

 and add to it dilute alcohol and de- 

 compose it with carbon dioxide. Filter this solution and re- 

 duce the solution somewhat by evaporation. Add 95 per-cent. 

 alcohol until a precipitate begins to form ; add a crystal of cane- 

 sugar to induce general crystallization and allow to stand. Cane- 

 sugar crystals are characteristic in form (See Fig. 83). 



If the above experiments indicate the presence of cane-sugar 

 and glucoses in the solution, the remainder of the extract should 

 be divided into two equal parts and treated as follows : 



I. Determine the quantity of reducing sugar (glucoses and 



FIG. 83. Crystals of cane-sugar. 



