Experiments and observations on shell and bone / [Charles Hatchett].

  • Charles Hatchett
Date:
[1799]
Catalogue details

Licence: Public Domain Mark

Credit: Experiments and observations on shell and bone / [Charles Hatchett]. Source: Wellcome Collection.

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    9 by a very small portion of gluten; and that mother of pearl and pearl do not differ from these, except by a smaller proportion of carbonate of lime; which, instead of being simply cemented by animal gluten, is intermixed with, and serves to harden, a membranaceous or cartilaginous substance; and this substance, even when deprived of the carbonate of lime, still retains the figure of the shell. But, between these extremes there will, probably, be found many gradations ; and these we have the greater reason to ex¬ pect, from the example afforded by the Patellae, which have been lately mentioned. Some few experiments were made on certain land shells; and, in the common garden snail I thought that I discovered some traces of phosphate of lime; but, as I did not find any in the Helix nemoralis, it may be doubted whether the presence of phosphate of lime should be considered as a chemical character of land shells.* Experiments on the covering Substance of crustaceous Marine Animals As I was not acquainted with any experiments by which the chemical nature of the substance which covers crustaceous ma¬ rine animals had been determined, I was desirous to ascertain in what respect it was different from shell, and I began these * Some experiments which I have lately made upon the cuttle-bone of the shops, have proved, that the term bone is here misapplied, if the presence of phosphate of lime is to be regarded as the characteristic of bone ; for, this substance, in composi¬ tion, is exactly similar to shell, and consists of various membranes hardened by car¬ bonate of lime, without the smallest mixture of phosphate. f Under this head I have included my experiments upon Echini, Star-fish, Crabs. Lobsters, &c. B
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