appearance or become invisible, the proof was rendered complete. When, in place of the candle that had slowly burnt away, it was shown that certain calculable quantities of carbonic acid and water had resulted—when it was demonstrated that the joint weight of the carbonic acid and water thus produced, was equal to the weight of the candle plus that of the oxygen uniting with its constituents during combustion; it was put beyond doubt that the carbon and hydrogen forming the candle, were still in existence, and had simply changed their state. And of the general conclusion thus exemplified, the exact analyses daily made, in which the same portion of matter is pursued through numerous transformations and finally separated, furnish never-ceasing confirmations. Such has become the effect of this specific evidence, joined to that general evidence which the continued existence of familiar objects unceasingly gives us; that the indestructibility of Matter is now recognized by many as a truth of which the negation is inconceivable. Habitual experiences being no longer met by any counter-experiences, as they once seemed to be; but these apparent counter-experiences furnishing new proof that Matter exists permanently, even where the senses fail to detect it; it has grown into an axiom of science, that whatever metamorphoses Matter undergoes, its quantity is fixed. The chemist, the physicist, and the physiologist, not only one and all take this for granted, but would severally profess themselves unable to realize any supposition to the contrary. * * * * * § 67. This last fact naturally raises the question, whether we have any higher warrant for this fundamental belief, than the warrant of conscious induction. The indestructibility of Matter is proved experimentally to be an absolute uniformity within the range of our experience. But absolute uniformities of experience, generate absolute uniformities of thought. Does it not follow, then, that this ultimate truth must be a cognition involved in our mental organization? An affirmative answer we shall find unavoidable.