Alteration in the Colours of Flowers by Cyanide Fumes

Abstract

IT is well known that the yellows of some insects are turned to red by the fumes from potassium cyanide; but I have not, after some inquiry, been able to obtain any literature describing the effects of such fumes upon the colours of flowers. The reactions I have observed are very curious, and while it seems improbable that they are hitherto wholly unknown, it may not be amiss to direct attention to them. A few lumps of the cyanide are placed in a corked tube, covered with a little cotton, and the flowers are placed on the cotton. It is probably necessary that the day should be hot, or the tube slightly warmed. The pink flowers of Cleome integrifolia and Monarda fistulosa turn to a brilliant green-blue, and finally become pale yellow. A purple-red Verbena becomes bright blue, then pale yellow. The purple flowers of Solanum slæagnifolium go green-blue and then yellow. The white petals of Argemone platyceras turn yellow—the natural colour of A. mexicana. The pale yellowish flowers of Mentzelia nuda turn a deeper yellow. Flowers of Lupinus argenteus, var., turn pale yellow. White elder (Sambucus) flowers turn yellow. The scarlet flowers of Sphæralcea angustifolia turn pale dull pink, resembling somewhat a natural variety of the same. Any of your readers will doubtless obtain similar results with the flowers growing in their vicinity.