Experiment with Flowers. 71 



EXPERIMENT WITH FLOWERS. 



If the lobelia fulgens, which is of a pure blood-red, is viewed 

 by the light of an alcohol lamp, with a little salt added to the 

 wick, it becomes absolute black, which is not the case when ob- 

 served by solar, or chemical light. The scarlet geranium too, 

 naturally reflects a compound of red and yellow, but when seen 

 by the spirit lamp, with salt, appears yellow. Purple colours 

 under hke circumstances appear blue. If a candle is put on one 

 side of the lobelia, and a spirit lamp on the other, one half ap- 

 pears black, and the other, red. The explanation of this beautiful 

 experiment is suggested by the study of the nature .of reflecting 

 bodies, and of light. Coloured bodies are so formed, as to reflect 

 rays and combinations of rays, peculiar to them in their natural 

 state. Hence, red flowers reflect the red ray which they obtain 

 from light. But the light of a spirit lamp gives out — as may be 

 proved by a prism — no red ray, and hence the lobelia, when ob- 

 served by this light, has no red ray to reflect, and appears black. 

 The geranium receives no red ray, and appears yellow. The 

 purple receives no red ray, and appears blue. Those unac- 

 quainted with the properties of bodies and of light, are generally 

 contented to believe that the natural colour of an object belongs 

 to it inherently, as much as its form does. But this is not so. 

 Whatever the reflecting structure of bodies may ultimately de- 

 pend upon, they must be in connection with light before they 

 can reflect ; and as it is remarked, in a work that will perhaps 

 bear reading oftener than any other that modern times have pro- 

 duced, " Preliminary Discourse on the study of Natural Philoso- 

 phy, by John Frederick William Herschell," &c. &c. " when the 

 differently coloured prismatic rays are thrown, in a dark room, 

 in succession, upon any object, whatever be the colour we are in 

 the habit of calling its own, it will appear of the particular hue 

 of the light which falls upon it. A yellow paper, for instance, 

 will appear scarlet when illuminated by red rays, yellow when 

 by yellow, green by green, and blue by blue rays ; its own (so 

 called) proper colour not in the least degree mixing luith that it so 

 exhibits." 



Perhaps at some future day, light may be so managed, as to 

 admit of bodies reflecting particular colours, without adding the 

 expense of dying or painting to them. Editor. 



