382 
REPORT—1854. 
It being thought that the disproportionate weight of the plants which had 
grown in the dark might be partially owing to their not having become 
thoroughly air-dried in eighteen hour.'-, on account of their succulent cha¬ 
racter, they were exposed in the same manner for forty-eight hours. Their 
weight was then reduced to 66 grains, whilst those grown under the obscured 
colourless (succulent as they were) lost in the same time only 14 grains; 
and those under the obscured yellow appeared rather to have gained weight 
The increase in weight in those instances must he attributed, as in the caw 
of the wheat, to the absorption of water, and it seems to be in almost reverse 
ratio to the healthiness of the? plant ; for those under tire red, which had the 
best appearance at first, allowed by far the smallest increase iu weight; and 
those under the bine, which were afterwards better looking, had not incrca.**J 
greatly. 
In the comparative i-xperiment made without any glass shade, mic po 
began to germinate* on May 23rd ; this was shortly followed by two others, but 
only oiie of the three grew to any size. When measured on June Cth. it' 
root was found to be only 0*75 inch long; its stalk had attained a length c-t 
4**5 inches; its leaflets were deep given, appearing as healthy as '* ni ’J 
healthier than, any under the glass shades, and when removed from » 
moisture for eighteen hours, it weighed 5'5 grains, showing an increase 
2-7 grains on its original weight. 
On examining these results we. are led to draw the following conclusion • 
as far as peas are. concerned, growing under the conditions ol the expiri 
merit. The cutting off of the chemical rays favours the firatgermin#t |lin ^ 
the seed, and this appears to he the principal, if not the only fl'lvmi»r 
of the darkness obtained by burying the semis in the soil. The developing 
ol roots also requires the absence of the chemical ray, yet it does noth 
o the greatest extent when all the solar inlluencc?s art? excluded) 
favoured rather tlun otherwise by heat and luminosity. The totfW 
ment of the plume also proceeds best, under the same circumsance . 
^ e ,f re l * 1( ; conditions which produce, a healthy plant: d al ^ 
radiations be withdrawn. wh«>tlw*r ™iirpiv m- nnlv to a great ex 
„ , S rca tly impedes the growth of these plants ,. uD . 
shiner 68 n , t ie < x P c,, ment. As peas grow commonly m th 
aro p r W ° U ,‘ intt ' r08ti "K to observe whether the negativa result 
from im" 1 6 ab8f!nce of 80i > about the roots, from excessive nit ^ 
dptnr ■ • G 0t )^ r caU30, The experiment, however, affords us , c t(l 
t d hoT m !!! g !• "? ^ Ue8tion - The chemical Ibree is the most autago ^ 
ra PM .’ a,ul ‘"“dnosity also militates agBinst it. ^ 
tion of wh«* 7 .V 1 . eSect ot ' ,,,e various solar radiations upon ‘“^ c k 
the o-reat f i: v ' l . t . 1110 offect produced upon that of peas, we# c 
II* d r ! ty bct ^ e “ them. This was particularly 
to .ta„TSrh U ‘“? Xperiwcnt - The colouHess and the red 
former i-h,, t n"** , on tlle tab ie, and it was curious to no [tL n; o 
iormer glass a tall and vigorous crop of corn-plants with a mere 
