/Properties of the Filtered and Washed Residue./--The residue prepared as described above consists mainly of the protein, glycogen, and dextrins of the yeast-juice, and is almost free from mineral phosphates, but contains a certain amount of combined phosphorus. It also contains the enzymes of the juice, including the proteoclastic enzyme, and the hexosephosphatase (p. 54). Its solution in water is usually quite inactive to glucose or fructose, but in some cases produces a small and evanescent fermentation. When the original filtrate or a corresponding [p061] quantity of the filtrate from boiled fresh yeast-juice is added, the mixture ferments glucose or fructose quite readily. The following table shows the quantitative relations observed, the sugar being in all cases present in excess:-- ──────────────────────┬────────┬──────────┬────────┬────────┬────────── │ │ Filtrate │ Boiled │ Water │ CO{2} No. Material. │ Volume.│ added. │ Juice │ added. │ evolved. │ │ │ added. │ │ │ │ c.c. │ c.c. │ c.c. │ ──────────────────────┼────────┼──────────┼────────┼────────┼────────── 1 Undried and │ │ │ │ │ unwashed residue │ 15 c.c.│ 0 │ 0 │ 15 │ 0 g. │ 15 " │ 15 │ 0 │ 0 │ 0·035 " 2 " " │ 15 " │ 0 │ 0 │ 15 │ 0·024 " │ 15 " │ 0 │ 15 │ 0 │ 0·282 " 3 Undried and washed│ │ │ │ │ residue │ 25 " │ 0 │ 0 │ 0 │ 0·4 c.c. │ 25 " │ 0 │ 25 │ 0 │268 " 4 " " │ 20 " │ 0 │ 0 │ 0 │ 8·3 " │ 20 " │ 20 │ 0 │ 0 │ 90·3 " 5 Washed and dried │ │ │ │ │ residue │ 1 gram │ │ │ │ │ in │ │ │ │ │ 15 c.c.│ 0 │ 0 │ 0 │ 0 " │ " │ 0 │ 12 │ 0 │108 " 6 " " │ 1 gram │ │ │ │ │ in │ │ │ │ │ 25 c.c.│ 0 │ 0 │ 0 │ 0 " │ " │ 0 │ 25 │ 0 │364 " ──────────────────────┴────────┴──────────┴────────┴────────┴────────── [p062] These experiments lead to the conclusion that the fermentation of glucose and fructose by yeast-juice is dependent upon the presence, not only of the enzyme, but also of another substance which is dialysable and thermostable.