CH. VI.] THE FLOWER. 191 



chyma, that the coloui' of a petal depends ; foj sul- 

 phiu'ous acid, (the fume aising from a bmiiing match,) 

 which has a most powerful affinity for oxygen, destroys 

 the hue of all coloui-ed flowers, though it leaves that of 

 white flowers unchanged. Mr. Smithson's experi- 

 ments, and those of M. Schluber, seem to indicate 

 that the coloming matter of flowers and fruits is fun- 

 damentally blue — rendered red by acids or the ad- 

 dition of oxygen, or yellow by the presence of an al- 

 kali or the subtraction of oxygen. Mr. Smithson 

 says, that the coloming matter of the violet is the 

 same in the ruddy tips of the daisy, geranium, blue 

 hyacinth, hollyhock, lavender, and vaiious plums, in 

 the leaves of the red cabbage, and in the lind of the 

 salmon radish. The acid which causes the red tint 

 seems to be usually the carbonic. 



No seed ever attains the power of germinating, 

 unless the pollen from the stamens in the same, or 

 some nearly-allied flower has reached and impreg- 

 nated its pistils. This was known to the most an- 

 cient of the Greeks ; for Herodotus relates that the 

 cultivators of the date (Phoenix dactilifera) brought 

 the flowers of the barren plants, which they called 

 the males, and attached them to the finiitful trees, 

 that theii' produce might not fall without attaining 

 matmity, a phenomenon explained both by Anaxa- 

 goras and Empedocles, who flourished in the fifth 

 century before the Christian era, by claiming for 



