D bl ry a4 
42 J. M. Crafts on the Action of Bromine and of 
zomes of Psilophyton ; and it is only in the Upper Devonian 
that we find such stations occupied, as in the Coal-measures, by 
Sigillaria and Calamiites. 
hough the area to which this paper relates is probably 
equal to any other in the world in the richness of its Devonian 
Flora, still it is apparent that the conditions were less favorable 
to the preservation of plants than those of the Coal Period. 
The facts that so large a proportion of the plants occur in ma- 
rine beds, and that so many stipes of Ferns occur in deposits 
that have afforded no perfect fronds, show that our knowledge 
. of the Devonian Flora is relatively far less complete than our 
knowledge of that of the Coal-formation. 
, evonian Flora was not of Jower grade than that of 
the Coal Period. On the contrary, in the little that we know 
of it, we find more points of resemblance to the Floras of the 
Mesozoic Period, and of modern tropical and austral islands, 
than in that of the true Coal-formation. We may infer from 
this, in connexion with the preceding general statement, that, in 
the progress of discovery, very large and interesting additions . 
will be made to our knowledge of this Flora, and that we may 
possibly also learn something of a land Fauna contemporaneous 
with it. 
6. The facies of the Devonian Flora in America is very simi 
lar to that of the same period in Europe, yet the number of 
identical species does not seem to be so great as in the coal-fields 
of the two continents. This may be connected with the differ- 
ent geographical conditions in these two periods; but the facts — 
are not yet sufficiently numerous to prove this. 
7. The above general conclusions are not materially different 
from those arrived at by Goeppert, Unger, and Bronn, from a — 
consideration of the Devonian Flora of Baten 
ne OH 
Art. VI.—Action of Bromine and of Bromhydric Acid on the — 
Acetate of Ethyl; by J. M. Crarts.* ae 
Mr. Wurtz proposed to me to seek to obtain from the action 
of bromine on the acetate of ethyl a product of substitution — 
represented by the formula’ C,H,BrO,, in order to study its — 
reaction with the oars of silver in the presence of water. The — 
treatment with oxyd of silver and water, of products of ‘substi- — 
tution of bromine and iodine in organic radicals, serves to Te — 
place these elements, and Steak ast Ba equivalent of bydro- — 
gen, whose place they occupy, by the peroxyd of hydroge®, — 
* 
