Concerning the changes effected in the principles of the impregnated blood during circulation and its action upon the nervous and muscular fibre; it is useless to reason in the present state of our knowledge.
It would be easy to form theories referring the action of blood impregnated with nitrous oxide, to its power of supplying the nervousand muscular fibre with such proportions of condensed nitrogene, oxygene and light or etherial fluid, as enabled them more rapidly to pass through those changes which constitute their life: but such theories would be only collections of terms derived from known phænomena and applied by loose analogies of language to unknown things.
We are unacquainted with the composition of dead organised matter; and new instruments of experiment and new modes of research must be found, before we can ascertain even our capabilities of discovering the laws of life.