248 
POPULAR SCIENCE REVIEW. 
Distribution of Trichomanes radicans. — The Killarney fern, as it is 
termed in this country, is far more generally distributed than is usually 
imagined. In some of our popular works it is stated that the only sta- 
tions for it in the British Islands are Yorkshire and Kerry. This idea is 
incorrect. The late Professor Kinahan discovered it growing in profusion 
in the counties of Wicklow and Waterford, in Ireland, and now we have 
Mr. W. Gast’s authority for stating that it has been found in the northern 
half of the Scotch island of Arran. It may be remarked, that owing to 
the hyper-enthusiasm of botanists, this plant is no longer to be found 
growing in Killarney. 
Leaf-Cells of Hymenophyllum and Trichomanes . — Professor Gulliver 
states that there is hardly any distinction to be drawn between the leaf- 
cells of Trichomanes and those of Hymenophyllum Wilsoni , although the 
differences between H. Tunbridgense and each of the others are very well 
marked. 
Relation between the Colour of Leaves and Decomposition of Carbonic 
Acid . — In opposition to the views of M. Corenwinder ( vide Popular 
Science Review for October, p. 103), M. Cloez states that, although the 
leaves of certain plants appear to be of a reddish or brownish tint, if they 
be examined carefully, it will be seen that they always contain, inter- 
mingled with the ordinary colouring matter, but in an isolated state, a 
quantity of green substance. His experiments tend to prove that it is in 
virtue of this material that these leaves decompose carbonic acid, as 
demonstrated by M. Corenwinder. The apparent exception to the rule is 
that of Atriplex hortensis ) which, according to Saussure’s experiment, 
produced seven or eight times its volume of oxygen in four or six hours, 
although ail its leaves are red or purple. That this plant does decompose 
carbonic acid, M. Cloez admits, having seen it do so himself. He 
asserts that in the tissue of even its leaves there exists a certain quantity 
of green matter ; but this is masked by the presence of a violet-red prin- 
ciple, which may be isolated by chemical means. He took a common 
garden species of Amaranthus , and cut the leaves, which are green, red, 
and yellow, in such a manner as to separate the different coloured parts 
from each other. These were now placed in water whose gases had been 
expelled, but which was charged with carbonic acid, and then submitted 
to the action of light. It was found that the green parts alone produced 
oxygen , whilst the other portions (red and yellow) did not furnish the 
slightest trace of the gas, even after twelve hours’ exposure to the sun. 
The following were the conditions and results of the experiment : — Twelve 
grammes of the leaves were taken and were placed in a flask of about 
two litres capacity, previously filled with water containing a small 
quantity of carbonic acid. The flask was provided with an exit tube, 
and after twelve hours’ exposure, 245 cubic centimetres of gas were 
developed, whose composition, in 100 volumes, was that beneath : — 
Oxygen 85*64 
Carbonic Acid ... ... ... ... ... 1*24 
Nitrogen 13*12. 
100*00 
— Comptes Rendus , Nov. 16th.) 
