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It was true that to so general a principle there were some 
exceptions, in which the plant, instead of deriving its sustenance 
primarily from the inorganic world, utilized the elaborated juices of 
other plants, as in the case of the mistletoe, or derived its pabulum 
from either the decaying plant or animal, nay, in some cases, from the 
living plant or animal, as seen in the case of many fungi; but these 
were exceptions to the rule by which we could trace the changes from 
the inorganic to the vegetable, and from the vegetable through the 
animal back to the inorganic world. 
While tracing any of these changes, certain marked facts stood 
out, showing that, wheré inorganic matter had passed through organized 
bodies, and returned to the soil, the constituent élements had, as it were, 
acquired higher properties and had become elevated by passing through 
organized bodies. 
Thus if a portion of bare rock was exposed to the action of light, 
heat, and moisture, in a short time a greenish colour was seen to come 
_ over it, which, if: carefully examined, revealed the fact that spores of 
some cryptogamous plant had found a suitable wédus in which to 
germinate. Soon a moss or lichen made its appearance, to serve as 
food to some minute animals. Some portion of it decayed, the animal 
deposited its refuse matter, the wind caused particles of dust to settle 
and, in time, a small accumulation of soil was formed, in which the 
seed of a phcenogamous plant nestled and germinated, giving rise to 
a plant which could not have obtained either a foot-hold or an appro- 
priate pabulum, on the mere rocky surface. 
Or take what was so admirably shown some years since by Mr. Hollis 
ina paper on “Isomeric Substances.” How different was the action, 
whether as manures or medicines, of many chemical compounds when 
derived directly from the inorganic world or indirectly from organic 
substances ; thus, while the chemist could detect no difference between 
some salts obtained from organic and inorganic matter, the plant on 
the one hand discriminated ; and on the other, the effect, when 
exhibited as medicines, was diametrically different. This was notably 
the case in certain preparations into which phosphate of lime entered 
—that prepared from bones being positive in its action ; while that 
derived from the Rock of Estramadura was negative. It would seem 
that when primitive elements, as they might be called, passed through 
organisms they became more elevated in their nature and properties, 
