LUMINOUS FLOWERS. 123 



tiling else by their brilliant red, something like flame. We 

 placed ourselves before the plant, and looked steadfastly at 

 it, but could not see the flash again, till we chanced in pass- 

 ing and repassing to look at it obliquely; and we could 

 then repeat the phenomenon at pleasure. It appeared to be 

 an optical illusion, and that the apparent flash of light was 

 merely the spectral representation of the blossoms of a blue- 

 green." 



It is an interesting fact, that the light has been observed 

 principally about yellow flowers, as the sunflower (Helian- 

 thus annuus), the Rose d'lnde and Oeillet d'Inde, the garden 

 marigolds (Calendula), yellow lily, and others. 



The Swedish naturalist, Professor Haggern, was fortunate 

 in observing the light about the marigold. His first impres- 

 sion was, that it was an illusion ; and to convince himself, he 

 placed a man near at hand with orders to make a signal 

 when he saw the light : the result was, that both observed 

 it simultaneously. The light appeared as a flash, often in 

 quick succession from the same flower, and again only after 

 several moments. It was only observed at sunset on dry 

 days. Professor Haggern 's observations were made upon 

 the marigold, garden nasturtium (Tropceolum majus), the 

 orange lily (Lilium bulbiferum), and the French and African 

 marigolds (Tagetes patula and T. erecta). He was at first 

 disposed to consider the light due to some insect, but finally 

 decided that it was electrical. 



In 1857 the press of Upsala, Sweden, contained accounts 

 of remarkable lights that had been observed about a group of 

 poppies in the Botanic Gardens. The observer, M. Th. Fries, 

 a well-known botanist, in passing the flowers, noticed three 

 or four emitting little flashes of light. Believing that he 



