324 Messrs. A. Harden and W. J. Young. [Feb. 12, 



free from mineral phosphate and hexosephosphate, but containing total phosphorus 

 equivalent to 0-077 gramme MgoP^O^ per 25 c.c, were used. 



<i. 1 gramme residue + 2 grammes fructose + 25 c.c. coferment solution. 

 b. The same + 0'25 gramme crystallised sodium phosphate. 



Experiment 6. — a. 25 c.c. washed zymin suspension + 15 c.c. coferment solution + 

 2 grammes fructose. 



b. The same mixture + 2'5 c.c. of a 0-3 molar solution of sodium phosphate solution. 



All the experiments were carried out at 25°, in presence of toluene, and the results are 

 tabulated below. 





Experiment 



3. 



4. 



5. j 6. 



Gas evolved in absence of added phosphate ... 

 Gras evolved in presence of added phosphate ... 



Ratio of increase after initial period to original 

 fermentation 



c.c. 

 1 -4 



25 -8 



c.c. 

 1 -2 

 26 -8 



c.c. 

 20-3 

 92 -3 



c.c. 

 31 -2 

 187 -2 



24 -4 

 16-9 



25-6 

 16 -8 



72 -0 

 16 -8 



156 

 19 



7-5 



8-8 



55 -2 



137 



18-4 

 5-3 



21 -3 

 7-3 



4-5 

 2-7 



6 



4 -4 



III. Hydrolynis of Hexosephosphate hy Yeast-jniec leith Production of Free 

 Phosplidte and a Fermentable Sia/ar. 



(a) Production of free phosphate and a reducing substance. 



It l)as previously been sliown tliat free phosphate is produced by the action 

 of the enzymes of yeast-juice on the hexosephosphate formed during fermenta- 

 tion.* According to equation (2) above, this phosphate sliould be acconiijanicd 

 by a sugar, and the folh)wing experiment shows that tliis is actually tlie 

 case : — 



Experiment 7. — Potassium hexoHe{)hos])hate was incubated with an inactive liltration- 

 residue, so that no fermentation of any liberated hexoso could occur, and tlie amounts of 

 free phosphate and reducing substance formed were determined, allowance being made 

 tin- the riuaiitities produced by the iticubation of the residue and of the hexo.stipliosphate 

 eeparatoly. 



.'i graninies of an inactive liltratioii-n^sidue wore dissolved in water and made to 75 c.c, 

 and a solution of jwtassiuni hexosephospliale, free from glucose and free pliosphate, and 



* Harden and Young, 'Roy. S(,c I'roc.,' IS, 1!)()8, vol. 80, j). 2!)!). 



