196 Miscellanies. 
22 oz. of nickel, 18 oz. of copper, 5 oz. of zine, and the same quan= 
tity as before mentioned. If the zinc contains the least quantity of 
arsenic, the alloy will be a —Jour. de Connois. Usuelles, = 
12, p. 89. 
GEOLOGY. _ 
Cuvier anp Bronenrart’s report on M. Desuayes’ “ Tableau 
comparatif des coquilles vivantes avec les fossiles des terrains ter- 
tiaires de 1 Europe.” —Among the organized bodies preserved inthe 
strata of the earth, none are more abundant, more diffused, or more 
interesting to science, than shells. ‘Their rapid multiplication and 
their stony nature have contributed, at once, to their preservation in 
great numbers ; so that they furnish the most positive proofs of the 
céndition os the ambient fluid at the period when each bed was de- 
M. Sodayes has indertaken to examine the shells of each stra- 
tum, and to compare them with those of the superior and inferior 
layers, as well as with those now living in the ocean in different lati- 
tudes, with a view thereby, to ascertain whether there have been @ 
succession and extinction of races, and to discover how those of the 
races which have escaped the changes of the surface of the earth 
have been distributed throughout the various regions of the sea. He 
was well convinced that he could not arrive at any conclusions on 
this point that would be free from objections, until he had observed 
and compared the greatest possible number chen, — it was 
not genera but species which must be taken into at gen 
nera, which are only creations of the mind, Routt s supply 1 no © import> 
ant information, when they passed from one series of layers to anoth- 
er, while they did not pass in the same identical species. 
He has thus been able, by: unexampled assiduity, to bring togeth- 
er more than three thousand species of shells, of certain origin, and 
to arrange them in a tabular form, compared with the known order 
of the superposition of the beds; to show at what epoch each spe-. 
cies commenced and finished ; while, from the comparison of them 
with more than four thousand Sued species, he shows which of them 
have been preserved to the present time, and what kind of beds have 
deposited upon them since their appearance. ad 
M. Deshayes has thus become convinced that the shell matid 
may be vary distinctly divided into two grand series which corres- 
