127 



ing those which have some tint diflFerent from the green, contain 

 Erythrogen. 



The second tahle exhibits the result of the action of the reagents 

 upon white flowers, all of which, to the number of about thirty, 

 gave prooft of their containing Xanthogen, but no Erythrogen nor 

 tinted Chromule of any kind. 



The third table displays the results with yellow flowers, from 

 which the general inferences are, that the yellow Chromule varies 

 in its nature in different flowers ; that all those subjected to expe- 

 riment contained Xanthogen, and none of them Erythrogen. 



The fourth table exhibits the experiments with red flowers, and 

 aff"ords the general conclusions, that while the red chromule shews 

 considerable variety of character, red flowers contain both Xantho- 

 gen and Erythrogen in abundance. 



Tiie fifth table exhibits the results with twenty blue flowers, and 

 presented the general observations, that the blue Chromule varies in 

 its character in different blossoms, particularly in shewing very dif- 

 ferent degrees of solubility in water and alcohol, and in some pro- 

 ducing coloured, and in others colourless, solutions in both men- 

 strua; and that they contain both the colourable principles of Xan- 

 thogen and Erythrogen. 



The sixth table relates to ten orange flowers, which equally 

 shews that the orange Chromule differs much in one plant from 

 another, and that they contain both colourable principles. 



The seventh table relates to twenty purple flowers, and afforded 

 the same conclusions as the preceding. 



The eighth table exhibits the experiments made upon the tinted 

 Chromule found in other parts of plants, beside the corolla of the 

 flowers, e. g. the calyx, bractea, the coloured leaves of plants, fruits, 

 and surface of the roots, all which comported themselves as the 

 corresponding coloured Chromules of the flowers do. 



Litmus presented a solitary example, but a very interesting one 

 in this inquiry, of a substance abounding largely in Erythrogen, but 

 containing no Xanthogen. 



A table was also presented, exhibiting the general facts relative 

 to the power of sulphurous acid in decolorizing the Chromules of 

 plants. This acid, whether employed in its gaseous or liquid 

 form, does not decolorize the Chlorophyle of leaves. It does not 

 affect white flowers. It did not decolorize any one of about a 

 score of yellow flowers submitted to its action. Of thirty or 



