THE GEAPE. 35 



pitate of albumen was obtained. By determining the 

 quantity of nitrogen, the quantity of albumen was 

 found. 



0-316 of cell-walls, dried at 110 C. 235 F. gave 

 M. Ylaanderen 0*048 platinum, or 0*007 nitrogen. 

 Hence these cell-walls contain, in 100 parts, 14 parts 

 albumen, if we reckon 15*5 per cent, nitrogen in 

 albumen. 



The cell-walls of the pulp cells of purple grapes con- 

 sist therefore of 



Cellulose ^ gg 



Pectose ]" 



Vegetable albumen 14 



100 



This is a considerable quantity of albuminous matter. 

 That this was really vegetable albumen and not vege- 

 table gluten was proved by the treatment of the cell- 

 walls with boiling alcohol. After filtering, on the 

 addition of water, and evaporation, no vegetable gluten 

 was precipitated. The existence of vegetable albumen 

 in the walls of the pulp cells, which ferment in the 

 juice, is of the greatest importance in the fermenta- 

 tion, for which reason we shall recur to it again at a 

 later period. 



With respect to the grape juice, when cleared and 

 treated with alcohol, it yielded only a small deposit, 

 white and flocculent, and mixed with a crystalline 

 precipitate of the salts. This flocculent precipitate 

 might contain either pectose or gum, but neither 



