FREE BOOKS

Author's List




PREV.   NEXT  
|<   141   142   143   144   145   146   147   148   149   150   151   152   153   154   155   156   157   158   159   160   161   162   163   164   165  
166   167   168   169   170   171   172   173   174   175   >>  
possess only a very incomplete knowledge of the coloring matters of flowers. Their investigation involves difficulties which cannot be mistaken. The matters which color flowers are uncrystallized; they frequently change by the action of the reagents employed for their preparation; and, also, very brilliantly-colored flowers owe their color to very small quantities of coloring matter. On the nature of the coloring matters of flowers several opinions have been expressed. Some observers have assumed that flowers owe their color to only two coloring matters, one of which is termed anthocyan, and the other anthoxanthine. Others will find a relation between the green coloring of leaves, the chlorophylle, and the coloring matters of flowers. They support their opinion generally on the results of the elementary analysis of those different bodies; but all chemists know that chlorophylle has not yet been prepared in a pure condition. Probably, it retains various quantities of fatty and albuminous bodies. Further, the coloring matters of flowers are scarcely known, so that it is impossible to establish relations supported by the necessarily uncertain composition of impure bodies. Some time since the blue color of flowers was ascribed to the presence of indigo; but Chevreul has shown, in a certain way, that the blue substance of flowers is always reddened by acids; and that with indigo it is quite different, which, as is known, retains its blue color even when the strongest acids are allowed to act on it. It is thus seen that the coloring matters of flowers have heretofore only in a superficial manner been examined, and that it is important to again undertake their complete examination, as these bodies are interesting to the chemist, because they are employed as reagents in the laboratory for the recognition of alkalies; and by an improved knowledge of them the florist might find the way by which he could give to cultivated flowers various colors. We have believed that before undertaking their elementary analysis, methods must be carefully sought for which can be followed for the obtainment of the coloring matters of flowers, and that it should be proved whether these substances are to be considered as independent bodies, or whether they proceed from one and the same matter, which is changed in various ways by the juices of the plant. We now publish the results of our first investigations. _Blue Coloring Matter of Flow
PREV.   NEXT  
|<   141   142   143   144   145   146   147   148   149   150   151   152   153   154   155   156   157   158   159   160   161   162   163   164   165  
166   167   168   169   170   171   172   173   174   175   >>  



Top keywords:

flowers

 

coloring

 

matters

 

bodies

 

quantities

 

matter

 

knowledge

 

chlorophylle

 

reagents

 

results


analysis

 

elementary

 

employed

 

retains

 

indigo

 

chemist

 

laboratory

 

recognition

 
alkalies
 

interesting


manner

 
strongest
 

allowed

 

undertake

 

complete

 

important

 

examined

 

heretofore

 

improved

 
superficial

examination
 

methods

 

changed

 

juices

 
proceed
 
considered
 
independent
 

Coloring

 
Matter
 

investigations


publish

 

substances

 

proved

 

cultivated

 

colors

 

believed

 

florist

 

undertaking

 

obtainment

 

sought