14 TREATMENT OF THE SUBJECT-MATTER. 
is richer in atropine than that of seven years’ or still older 
growth, which is probably chiefly caused by the fact that this 
alkaloid is mainly contained in the bark, and in older roots the 
latter is relatively less in amount than in younger; the constitu- 
ents of belladonna leaves are not so variable in amount.' The 
fact that many fruits and seeds before ripening contain starch, 
and afterwards more sugar, oil, and other substances, will be 
explained further on when we shall consider the subject of 
amylum. In the juice of Aeballium Elaterium Richard, elate- 
rin occurs abundantly in July, but in September this powerfully 
drastic, crystallizable body is wanting therein.” Pepper, cubeds, 
and cloves are richer in volatile oil before ripening; the Cinchona 
barks may occasionally be poor in quinine, or even contain none 
at all. 
It is self-evident that the quality of the soil must also have 
some influence upon the chemical development of the plant. 
Valerian root grown in dry localities is richer in volatile oil 
than that in moist ground, and in the case of Taraxacum, the 
root, from a chemical point of view, shows great variations, ac- 
cording to locality and the time of year. The red Flores Mal- 
ve become blue, and gentian root, which in the interior is purely 
white, becomes colored yellowish-brown, unless the water is 
abstracted from it with the most extreme care. Flores Rhoea- 
dos do not even then retain their color, while, on the other hand, 
the remarkable brown coloration of Flores Verbasci may easily 
be avoided. The Cinchona barks also assume, during the pro- 
cess of drying, another color.* 
Still other changes occur when the drugs are scalded, or are 
‘Lefort, Journ. de Pharm. et de Chim., XV. (1872), pp. 268, 421; . 
Gerrard, Pharm. Journ., XV. (1884), p. 153. Compare further, Dragen- 
dorff, ‘‘Chemische Werthbestimmung stark wirkender Droguen,” 
St. Petersburg, 1874. 
* Kohler in Buchner’s Repertorium der Pharm., XVIII. (1869), p. 590. 
* The changes which the green coloring-matter of. plants undergo 
upon drying, and the ways and means to be resorted to in order to re- 
duce these changes to the smallest compass, have been thoroughly eluci- 
dated by Tschirch: “‘ Einige practische Ergebnisse meiner Untersuchun- 
gen tiber das Chlorophyll der Pflanzen,” in Archiv der Pharm., 222 
(1884). . 
