There are some remarkable facts connected with Animal Chemistry—if we may employ the term—which show how superior is the principle of Life to all known methods of synthesis and analysis. For example, much more carbon or charcoal is regularly voided from the respiratory organs alone, of all living beings—not to speak of its ejection in many other ways—than can be accounted for, as having in any way entered the system. They also produce and eject much more nitrogen than they inhale. The mushroom and mustard plant, though nourished by pure water containing no nitrogen, give it off abundantly; the same is the case with zoophytes attached to rocks at the bottom of the sea; and reptiles and fishes contain it in abundance, though living and growing in pure water only. Again, plants which grow on sand containing not a particle of lime, are found to contain as much of this mineral as those which grow in a calcareous soil; and the bones of animals in New South Wales, and other districts where not an atom of lime is to be found in the soil, or in the plants from which they gather their food, contain the usual proportion of lime, though it remains an entire mystery to the chemist where they can have obtained it. The same fact is observable in the egg-shells of hens, where lime is produced in quantities for which the kind of food taken is altogether inadequate to account: as well as in the enormous deposits of coral-rock, consisting of almost pure lime, without any manifest supply of that ingredient. Chemistry fails to unravel these mysterious facts; nor can it account for the abundant production of soda, by plants growing on a soil containing not an atom of soda in any form: nor of gold in bezoards; nor of copper in some descriptions of shell-fish. These extraordinary facts seem to point to this—that many, if not most, of the elements which chemists have set down as simple, because they have failed to reduce them further, are in reality compound; and that what we regard as Elements, do not signify matters that are undecompoundable, but which are merely undecompounded by chemical processes. Life, however, which is superior to human powers of analysis, resolves and composes the ultimate atoms of things after methods of its own, but which to chemists will probably ever remain involved in mystery.