802 
2d Series of experiments. Enzyme R diluted with 3 vol. of water. 
Phos- | NaOH H,O Amy- En- Reduc- Rotation | 
phoric acid tion . = 
Nr. olution lum | zyme) Gr lodine reaction Py 
ae. EIC: WC) es C.C. Cas minutes | 
Reduction | 
1 10 13) 427 200 2 Py nee le be blue 4.53 
| perceptible 
2 10 13.5 |26.5| 200 | 2 | 180.10 | 188  |blue, shade of violet) 5.33 
| | 
3 10 14 (26 200 2 | 234.80 186 (violet, shadeof blue 5.86 
4 10 14.5 |25.5} 200 Ar A © Se «| oc eel violet 6.05 
5 10 15-125 200 By RS 186.5 violet,shade of blue 6.24 
6 10 15.5 (24.5) 200 2 22860: 18870 violet-blue 6.30 
7 10 tie 123 200 2 179.10 191.6 blue, shade of violet 6.61 
8 10 20 20 200 2 
105.40 195 blue 7.01 
jd Series of experiments. Enzyme D. 
Reduc- 
Phos- | ct 
Nr. panne ae eel ee ee Wie sion, ee lodine reaction | Py 
ies | CC. CC CC. ic. Cu minutes 
1 10 13.2 26.8 200 2 | 106.45 | 194 blue 4.90 
2 10 13.5 |26.5/ 200 | 2 | 194.50 | 190.3 blue, shade ofviolet) 5.52 
3 10 14° 126 | 200: JS 2) 2) 25125 4 190 violet-blue | 5.83 
4 10 14.5 |25.5| 200 2°.) 2290.10 | 189.7 violet, shade of blue! 6.08 
5 10 15 |25 | 200 22720 | 188 violet 6.19 
6 10 15.5 |24.5| 200 2 265.55 191 violet, shade of blue 6.37 
7 10 17) (23:41 +200 2 220.55 | 192 violet-blue 6.61 
8 10 20 \20 | 200 2 | 156.60 | 195 blue 71.03 
From these experiments it appears, that the concentration of the 
hydrogen-ions exerts a considerable influence upon the action of the 
enzyme; further that an increase of cy, consequently a decrease of 
py accelerates its activity, until a certain optimum is reached, after 
which the action slackens again. We also observe the same beha- 
viour with enzymes from different sources, however with a noticeable 
difference in their activity. From another series of experiments 
we gathered that the optimal reaction lies at about the same point 
in much more dilute phosphate solutions; we also learnt, that all 
over the series the action of the enzyme was more vivid. It follows 
