"392 Scientific InteUlgence. — Botany. 



was taken to siak each vessel one inch and a half in the ground. 

 These were all placed on a shelf, raised to one-half the height of 

 a lightsome window. The fourth day of the experiment the 

 radicles had shot out under all the vessels, and attained the 

 length of from one to two millimetres. The sixth day it was 

 observed that the vegetation was much more advanced under 

 the vessels than in the open air, and under the influence of the 

 compound light. Under the yellow, and particularly under the 

 bright yellow, the radicles were scarcely more developed than on 

 the fourth day. Under the green rays there were some radical 

 bairs towards their upper part, which was somewhat yellow. The 

 small plumulae were yellow ; the radicles and hairs were also as 

 under the yellow rays. The orange, red, purple, blue, and violet 

 rays, corresponded to radicles of a centimetre, yellow in the neck, 

 to radical hairs of a millimetre, to plumulas frequently curved 

 and well formed. Oa the seventh day the plumula? were developed 

 under all the vessels ; they were very yellow. Under the white 

 light they were becoming sensibly green ; in the open air they 

 appeared green. On the eighth day the shoots were from one to 

 one and a half centimetre in length; under the yellow rays they 

 were not so long, white all over, the plumulae yellow, the leaves 

 the same, and bent back, the radical hairs two millimeters in 

 length. Under the white light the shoots were scarcely three 

 milhmetres in length ; they were becoming green, as also the 

 leaves. On the ninth day there was an identity of character 

 with respect to all the plants under the vessels ; shoots of three 

 centimetres, leaves of four milhmetres, curved back very much, 

 entirely yellow. In the air, the shoots were scarcely a centi- 

 metre in length, the leaves very green. On the fifteenth day 

 of the experiment there was observed, at length, a strange 

 difference with respect to the plants developed under the yel- 

 low rays, their leaves were become green, though paler than 

 those plants in the open air. Under the orange rays a slight 

 greenness presented itself. Under all the other rays the plants 

 were evidently suffering, and were yellow. — From these re- 

 searches the author concludes, 1. That, in the same way as dark» 

 iiiss favours the first period of germination, so also do the colours 

 of the spectrum, acting separately, possess a specific influence 

 which seconds this operation ; but that among these colours, those 

 whose illuminating power (with the exception of green) is great- 



