(25) 
Physiology of Plants. — Professor BrIJERINCK presents a paper 
on: „Photobacteria as a Reactive in the Investigation of 
the Chlorophyll-function.” 
If in a mortar leaves of some neutrally reacting plant, e.g. of 
white clover are crushed, diluted with destilled water, and filtered, 
a green filtrate is obtained, in which are found that portion of the 
living protoplasm which is soluble in water, and many chlorophyll- 
granules which give the filtrate a green colour. 
If this green liquid is mixed with a culture of phosphorescent 
bacteria in fish-broth with 3 pCt common salt, or with sea-water ') 
rendered phosphorescent by a „luminous bouillon”, and if this mix- 
ture is filled into a test-tube or stoppered bottle, the liquid becomes dark 
as soon as the oxygen has been used by the physiological processes 
of the phosphorescent bacteria and of the living protoplasm of the 
clover-leaves in the filtrate. 
If the dark liquid is exposed to light, it is evident that the chlorophyll 
and the living protoplasm have not become inactive by the said 
treatment, for, by production of oxygen, they again cause the luminosity 
of the bacteria. Jf the plant-juice is fresh and the bottle is placed for 
a minute or longer in the full sun, then so much oxygen is formed, 
that the bacteria, transferred to the dark can continue phosphorescing 
for some minutes. 
This experiment is of an extreme sensibility, for even the lighting 
of a match is sufficient, after part of a second already, to produce 
a distinct phosphorescence which, of course, can only be observed when 
by remaining long enough in the dark, the eye has become sensible 
to feeble light. 
If the liquid is left to stand for some hours, either as such or 
after mixing with the phosphorescent culture, the power of decom- 
posing carbonic acid gets quite lost. Evidently the presence ot 
living protoplasm is necessary for it. Concequently, FRIEDEL’s2) 
experiment, wherein clear, filtered juice of squeezed spinage-leaves, 
mixed with powdered leaves of the plant, dried at 100° C., causes 
decomposition of carbonic acid, does not prove, as FriepEL thinks, 
that the function of chlorophyll reposes on the action of enzymes, 
but on the fact, that the portion of the protoplasm concerned in the 
1) By vsea-water” is meant tap-water with 3 pCt. Cl Na. 
*) J. Frrepen, Assimilation chlorophyllienne réalisée en dehors de l’organisme 
vivant. Comptes rendus T. 182, pag. 1188, 6 Mai 1901, 
