CHEMICAL COMPOSITION OF HOOT. 



441 



Tartrate of lime and potash, 



Potash, as sulphate and chloride, . 

 Phosphate of lime and magnesia,.. 



Silica, 



Oxide of iron, 



Water, 



, 8-0 

 2-0 



. 7'5 



, 1-5 



0-5 



8-0 



100-00 



The inorganic constituents of the roots have been de- 

 termined by Kochlin and by May as follows: 1 



Zeeland 



.Madder. 



Alsace Maddei-. 



The relative proportions of some of the ingredients, as 

 will be seen, vary considerably, especially between the 

 samples grown in the two different countries, the per- 

 centage of lime in the Alsace greatly exceeding that con- 

 tained in the Dutch madder, while the latter contains 

 phosphoric acid, silica, and soda in excess. 



These differences no doubt are mainly due to the dif- 

 ference in the composition of the soils in which they were 

 grown. It appears also that the constituents of the soil 

 exercise a marked influence on the colouring principles 

 contained in the root, as it is well known that Zeeland 

 madder contains more of the yellow and less of the red, 

 than that grown in the Vaucluse or other good districts 

 of France. 



1 Revue Scien. et Indus., tome xxiv. p. 77. 



