142 HOW CROPS GROW. 
lower leaves exhibited an increase of fixed matters after 
the first period, while in the upper leaves the ash dimin- 
ished toward the third period, and thereafter increased. In 
the ears, and in the entire plant, the ash decreased quite 
regularly as the plant grew older. Pierre found that the 
proportion of ash of the colza, (Brassica oleracea,) dimin- 
ished in all parts of the plant, (which was examined at five 
periods,) except in the leaves, in which it increased. 
(Jahresbericht tiber Agriculturchemie, III, p. 122.) The 
sugar beet, (Bretschneider,) and potato, (Wolff,) exhibit 
a decrease of the per cent of ash, both in tops and roots, 
In the turnip, examined at four periods, Anderson, 
(Trans. High. and Ag. Soc., 1859—61, p. 871,) found the 
following per cent of ash in dry matter: 
July% Aug. 11. Sept.1. Oct. 5. 
VICaVeS ie: cajesn sid: ce ccine siecae ais 7.8 20.6 18.8 16.2 
BONG sisisccsacainsatee cies ooo ees 5 17.7 8.7 10.2 20.9 
In this case, the ash of the leaves increased during about 
half the period of growth from 7.8 to 20,6, and thence di- 
minished to 16.2. The ash of the bulbs fluctuated in the re- 
verse manner, falling from 17.7 to 8.7, then rising again to 
20.9. 
In general, the proportion of ash of the entire plant 
diminishes regularly as the plant grows old. 
5. The influence of the soi/in causing the proportion of 
ash of the same kind of plant to vary, is shown in the fol- 
lowing results, obtained by Wunder, ( Versuchs-Stationen, 
IY, p. 266,) on turnip bulbs, raised during two successive 
years, in different soils, 
In sandy soit. In loamy soil. 
“4st year, 2d year, “Ast year, 2d year. 
Per cent of ash....18.9 113 9.1 10.9 
6. As might be anticipated, different varieties of the 
same plant, grown on the same soil, take up different 
quantities of non-volatile matters. 
In five varieties of potatoes, cultivated in the same soil 
