9 
the erection of the poor man’s dwelling. In visiting the mansions 
of the rich, we shall in general find, that, in proportion to the wealth 
and consequence of the possessor, will the more solid parts of the 
building be composed of these remains of animated beings, which 
lived in a former world. For the external part of such buildings, 
the architect finds no substance so well adapted, from its durability, 
and its easy yielding to the instrument, as the various kinds of 
coarser limestones ; nor for the more fine, internal and ornamental 
work, any substance so well calculated, by its fineness of texture, 
and pleasing appearance, to unite the advantages of strength and 
beauty, as the various marbles. 
Although insuperable difficulties oppose that theory, which attri- 
butes the formation of all these substances, to the decomposition of 
certain kinds of animal matter ; yet I have no hesitation in asserting 
that a very considerable portion of those masses owe their origin to 
that process. Seldom is a block of limestone severed, but the cut 
surfaces show the vestiges of animals, or rather of their domiciles ; 
and frequently, the polished slab of marble will be found to be 
almost wholly composed of similar remains. Thus we perceive that 
matter is in constant motion ; being impelled in regular progression, 
through various forms, and modes of existence : being thus made to 
perform those important functions, on which the life, as it were, of 
this globe depends. 
The study of animated nature affords more amusement, and 
excites more general attention, than, perhaps, any other department 
of natural history. It yields to the mind the amplest gratification, 
by the positive and indubitable information it conveys, respecting 
the varying economy, and the curious instinctive habitudes, which 
distinguish the numerous species of animals ; and by displaying the 
ahnost insensible shades of difference, by which the varieties of 
each species are distinguished, and the more marked and striking 
contrast, by which each species is separated from the other. Nor 
VOL. I. c 
