34 REPORT—1846., 
inconstancy of effect. One class of rays, the same to which Sir J. Herschel 
has given the name of Parathermic rays, are so subdued by the influences of 
the more refrangible rays, as to be nearly inactive during the spring and early 
summer months; and indeed in the spring they scarcely produce any effect 
upon dead vegetable colouring matter, unless their action is assisted by the 
use of some decomposing agent, such as sulphuric acid. These rays increase 
in power towards the autumn, and to them appears to be due the browning 
of the leaf. 
It is well known that plants will grow in the dark, but that they do not 
then form chlorophylle; the formation of this colouring-matter has been an 
object of some attention, and I believe I have determined it to result from 
the joint influence of the luminous and actinic rays. Boxes of cress have been 
grown in the dark, and they have then been brought under the influence of 
a large spectrum formed by a water-prism. It has been stated by Dr.Gardner, 
that the plants under those circumstances exhibit a lateral movement, bend- 
ing towards the yellow ray. This appears to bea mistake; the plants under 
the influence of the red rays bend from the light but along the line of the ray ; 
and those exposed to the most refrangible rays turn towards it, but still in the 
line of the ray. Now the plants which first become green, by careful treatment 
in this way, are those which are exposed to the rays situated between‘the mean 
green ray and the extreme blue. The action is continued eventually to the edge 
of the most refrangible violet below the yellow ray. There is not any change 
effected beyond the visible spectrum, notwithstanding the abundance of dark 
chemical rays ; and the change is slow where there is really the largest amount 
of light. I therefore conclude that the luminous rays are essential in the pro- 
cess, producing the decomposition of the carbonic acid and the deposition of 
the required carbon, which is afterwards. in all probability, combined with 
hydrogen under the influence of purely chemical force as exerted by the ac- 
tinic principle. 
Such ate the main results I have obtained. I have several experiments 
now in progress, and I hope to be enable? in another year to complete this pars 
ticular branch of investigation so far as to present to the British Association a 
complete report. 
Report on the Recent Progress of Analysis (Theory of the Comparison of 
Transcendentals). By R. L. Wuxis, M.A. 
1. Tue province of analysis, to which the theory of elliptic functions belongs, 
has within the last twenty years assunied a new aspect. A great deal has 
doubtless been effected in other subjects, but in no other I think has our 
knowledge advanced so far beyond the limits to which it was not long since 
confined. 
This circumstance would give a particular interest to a history of the ree 
cent progress of the subject, even did it now appear to have reached its full 
development. But on the contrary, there is now more hope of further pros 
gress than at the commencement of the period of which I have been speaking. 
When, in 1827, Legendre produced the first two volumes of his ‘ Théorie 
des Fonctions Elliptiques,’ he had been engaged on the subject for about 
forty years; he had reduced it to a systematic form; and had with great 
labour constructed tables to facilitate numerical applications of his results. 
But little more, as it seemed, was yet to be done; nor does the remark of. 
