4.0 Natural History of Molluscous Animals : — 
a very little lime, or perhaps none at all. If you ask me how 
Haire can be, I can only answer that it is one of the wonderful 
and inexplicable effects of a living principle. But the fact 
being as I have stated, you will readily grant that such a gift 
“as not likely to be bestowed for a minor purpose ; and though 
we cannot unfold all the uses of this metamorphosis of matter, 
yet we know enough to prove its vast import ance. ‘* Chalk, 
marl, and limestone,” says Buffon, ‘ consist entirely of the 
dust or fragments of shells.” * This, at first, may seem an 
extravagant doctrine, and Imagination herself startles when 
she attempts to sum up the millions and tens of millions which 
must have gone to the formation of such deep and extensive 
strata. It is nevertheless, in a great measure, true +3 and, as 
a proof of it, I will have pleasure in showing you, when next 
you visit me, strata of limestone, some miles i in extent, and 
many feet deep, composed almost wholly of shells, AR RECE 
of which are so well p reserved, that you may give them a 
“local habitation and a name” in the systems of naturalists. 
Cast a glance at your marble chimney-piece, and you will, in 
all probability, trace therein the figures of shells that have 
been, not the sportive freaks of the formative powers of nature, 
as philosophers once believed, but the true remains of living 
creatures which ‘* have put off flesh and blood, and are be- 
come immutable.” Hence it is that the study of shells, so 
long ridiculed by the wits of the age, as an abuse of time and 
waste of money, becomes so important, or rather necessary, to 
all those who make the structure of ane earth, and the various 
changes which it has under gone, an object of attention. “ For 
shells are found in abundanee.1 in a great variety of rocks and 
positions: they constitute the medals of the ancient world ; 
and, from an accurate acquaintance with their different spe- 
cies, and with the nature of the animals that inhabited them, 
many curious and important deductions respecting the form- 
ation and changes of the crust of the earth may be drawn.” + 
It is from their composition that even recent shells become 
useful as a manure, a purpose to which they are occasionally 
applied in this and other countries; and it has been ascer- 
tained by comparative experiments, that, on turf lands in par- 
* Nat. Hist., vol. i. p. 214.5 also vol. ii. p. 221., &c. The word shell is, 
however, used here in a very extensive sense, so as to include corals, madre- 
pores, Hchini, &c. ; still it does not materially affect the text. 
+ “ If Saussure,” says Dr. Clarke, “had not discovered limestone lying 
beneath rocks of the most ancient formation, the French would long ago 
have established a theory that all the strata of carbonated lime, upon the sur- 
face of the globe, have resulted from the decomposition of animal matter 
deposited during a series of ages.” See his Travels, vol. i. p. 624—26. 4to. 
{ Thomson’s Hist. of the Roy al Society, p. 83. 
