But since all animals ultimately derive their nourishment from vegetables, the chemistry of this order of beings must consist merely in the conversion of vegetable into animal matter.
MRS. B.
Very true; but the manner in which this is effected is, in a great measure, concealed from our observation. This process is called animalisation, and is performed by peculiar organs. The difference of the animal and vegetable kingdoms does not however depend merely on a different arrangement of combinations. A new principle abounds in the animal kingdom, which is but rarely and in very small quantities found in vegetables; this is nitrogen. There is likewise in animal substances a greater and more constant proportion of phosphoric acid, and other saline matters. But these are not essential to the formation of animal matter.
CAROLINE.
Animal compounds contain, then, four fundamental principles; oxygen, hydrogen, carbon, and nitrogen?
MRS. B.
Yes; and these form the immediate materials of animals, which are gelatine, albumen, and fibrine.
EMILY.
Are those all? I am surprised that animals should be composed of fewer kinds of materials than vegetables; for they appear much more complicated in their organisation.
MRS. B.