Sc kune k . — The Chemistry of Chlorophyll, iii 
This conclusion seemed to be confirmed by an experiment 
made in an atmosphere of hydrogen gas. One pound of 
green ivy leaves and the same weight of holly leaves were 
each placed loosely packed in a large flask, into which well- 
washed hydrogen gas was passed for several hours. The 
flasks being left to stand over night, hydrogen was again 
passed in, so as to remove any gas that might have diffused 
out of the leaves. A small quantity of aniline was then 
introduced into each flask and the leaves were moistened 
as uniformly as possible with the liquid, after which they 
were left to stand well covered for a day or two. In neither 
case was the least change of colour apparent in the leaves. 
When treated with boiling alcohol they afforded extracts of 
the usual chlorophyll-green colour, and these extracts, when 
examined in the manner before described, yielded no trace 
of anilophyll. Nevertheless, the conclusion to which this 
experiment would naturally lead, that it was the absence 
of oxygen that was the cause of the negative result in this 
case, was rendered uncertain by the next experiment, in 
which leaves of the same kinds were taken, the hydrogen 
being however replaced by carbonic acid gas. Here the 
leaves after contact with aniline turned brown as rapidly as 
in air, and the amount of anilophyll obtained seemed to be 
the same as usual. It would appear therefore that it is rather 
carbonic acid than oxygen that is required in this process, 
and that in the experiment with hydrogen it was the removal 
by diffusion of the carbonic acid present in the leaves that 
led to the negative result obtained. The experiments are, 
however, too few to justify very positive conclusions. I hope 
to resume them at a more favourable season when a greater 
variety of material to work upon will be available h 
1 I venture to express the wish that others who may be working at the chemistry 
of chlorophyll will allow me a little time to continue undisturbed my experiments 
on this part of the subject. The reaction above described was only discovered in 
the summer of 1888, and before I had advanced very far in its study the green 
foliage of the season had faded. I intend, health permitting, to continue my ex- 
periments in the approaching spring. 
