212 Dr. Matox's and Mr. Rackett's 
MR. HATCH ETT 
is the only author, with whose writings we are acquainted, that has 
scientifically investigated what may be called the chemical cha- 
racters of shells; a comparison of which with those derived from 
external structure cannot but be highly curious and interesting to 
the philosophical naturalist. To the disciple of Linnaeus it is 
peculiarly satisfactory to perceive that so many of Mr. Hatchett's 
experiments tend to establish the propriety of distinctions adopted 
by that illustrious naturalist. We would only refer the reader to 
the instance of the Echinus, the chemical characteristic of which 
genus proves, in opposition to Klein, the correctness of Linnaeus, 
in placing it among the crustaceous instead of the testaceous 
tribe ; the presence of the phosphate of lime detected in the cover- 
ing of the Echinus distinguishes the latter from testaceous sub- 
stances, which consist only of carbonate of lime mixed with the 
gelatinous matter. When one science can thus be made to remove 
unavoidable ambiguities in another, a beautiful example is esta- 
blished of the intimate connection that subsists between all the 
various branches of natural knowledge. 
In the year 1799 
MR. DONOVAN 
began the publication of the Natural History of the British Shells, 
including figures and descriptions of all the species hither- 
to discovered in Great Britain, systematically arranged in the 
Linnean manner, with scientific and general observations on 
each. Of this work five volumes in octavo have appeared, com- 
prising 180 plates, with coloured figures ; but, as it is not yet 
completed, we have only to observe, that the author has given 
several new species, and that he has rectified many errors of pre- 
ceding writers. 
The 
