( 603 ) 
Fermentation velocity in cM3. CO,, evolved per second. 
| 40 grs. yeast | 12 grs. yeast | 6 grs. yeast 16 grs. yeast 
785 cM’. H,O 32.8 cM3 H.O|34.8 cM‘. HO 31.4 cM*. H,O 
cM®. CO‚. 25 cM3. gluc. sol. 10 cM°.gluc.sol./10cM’.gluc sol. 10 cM’. gluc. solution 
temp. 40. temp. 45°. temp. 45°. temp. 45°. 
O5 0.452 | 0.135 0.106“ | 0.457 0.179 
5—10 0.250 | 0.009 | 0444 | 0.950 | 0.969 
10—15 0.357 0.953 0,190; ole O:31%<, | > 0.933 
45—20 0.417 DEN 0.190 | 0.357 | 0.385 
20-25 0.500 | 0.327 | 0200 | 0.333 0 419 
Deen oes | © 0.399 0.208 | © 385 0.417 
30-35 | 0.695 Oes57 (A Re gonad: 1 MORT 0.357 
35—40 | 0.625 Oso | 0.290 0 385 OS 
4045 | 0.625 ORDE 5 908% wk order |) 05385 
J SRO San 2 ke (es ag aed a 
50—55 | Oss. | 0.200 | O0 417 0.417 
55—60 | O33 ens 0.208 0 454 0.455 
G0—65 | 0.417 0.417 
seems however, that we can get out of this difficulty by an other way. 
For all non-lasting-noxious temperatures the fermentation velocity 
— and after our experience the same holds good for very different 
physiological processes ') — attains after a relatively short period in 
which an irregular rate is observed, a constant value which is 
maintained much longer than the first irregular course. That constant 
value, now, proves at a fixed regulation of the circumstances which 
govern the process, exclusively dependent on the temperature. Hence 
it is evident that the relation should be sought between that velocity, 
and the temperature and to fix for that velocity the temperature- 
1) It is a fact that also for physico chemical reactions a certain time must be 
allowed to pass before the process proceeds with the theoretically expected velocity. 
This is particularly obvious in photo chemicai processes; nol before the end of 
the so-called “photo-chemical induction time” the quantity cf converted matter 
becomes proportional to the product of time and light intensity (compare for 
instance Nernst, Theor. Chemie, 2 Aufl, S 603). Now, certainly nobody when 
studying the temperature-coefficient of the photo-chemical process, will be desirous 
to trace the initial velocity existing at the beginning of that induction time. 
