| matter } | 8.8777| 4.2370 | 7.7400 | 6.2910 |Humine | 0.8850| 0.3450 | 0.0700 | 0.0840 |Humic acid | 0.1340| 0.0310 | 0.6800 | 0.3600 |Apocrenic acid | 0.1533| -- | -- | 0.0929 |Water | 2.6840| 1.7670 | 2.7000 | 4.5750 | |--------|----------|---------|------- | | 12.7340| 6.3800 | 11.1900 |11.4020 | |========|==========|=========|======= |Sum of all the | | | | | constituents |100.1169| 100.2960 | 99.8447 |99.8571 | | AMOUNT OF CARBON, HYDROGEN, NITROGEN, AND OXYGEN | CONTAINED IN 100 PARTS OF EACH SOIL. | |Carbon | 4.510 | 1.3060 | 2.55 | 2.03 |Hydrogen | 0.550 | 0.3324 | 0.71 | 0.53 |Nitrogen | 0.220 | 0.0973 | 0.21 | 0.17 |Oxygen | 4.918 | 3.1001 | 5.08 | 4.09 | |--------|----------|---------|------- | | 10.198 | 4.8358 | 8.55 | 6.82 --------------------------------------------------------------- In examining these analyses, it is particularly worthy of notice that by far the larger proportion of the substances soluble in water consists of organic matter, lime, and sulphuric acid, the two last being in combination as sulphate of lime, while some of those substances which are usually considered to be the most important mineral constituents of plants are present in very small quantity--potash, for instance, forming not more than 1-25,000th of the whole soil, and phosphoric acid being entirely absent. On the other hand, this portion contains the whole of the chlorine which exists in the soil, and this might be anticipated from the ready solubility in water of the compounds of that substance. The portion soluble in acids consists of alumina and oxide of iron, both of which are comparatively unimportant to the plant, but very important, as we shall afterwards see, in relation to the physical properties of the soil. The remainder of the substances soluble in acids, amounting to from 1 and 2 per cent, is composed of some of the most essential constituents of plants. Lime, magnesia, potash, and soda, appear again in larger quantity than in the soluble part, and along with them we have the phosphoric acid to the amount of from 0.2 to 0.4 per cent of the whole soil, and sulphuric acid in much smaller quantity.