16. Though we say that plants and animals are formed of the same constituents as minerals, it is necessary to understand this statement in a purely material sense, as it has reference only to the body.
Without speaking of the intelligent principle, which is a question by itself, there is in organic matter a special indiscernible principle, which has never yet been defined: it is the vital principle. This principle, which is active in living beings, though extinct in beings deprived of life by death, nevertheless gives to them characteristic properties, distinguishing them from inorganic substances. Chemistry, which decomposes and recomposes the greater part of inorganic bodies, has power to decompose organic bodies, but has never known to reconstruct even a dead leaf, which is a conclusive proof that there is something in one which does not exist in the other.