Fan. 27, 1870 | 
NATURE 
345 
the superficial beds into too many separate deposits, though the 
facts brought forward were of great value. Mr. Evans mentioned 
that he had received information of the discovery many years 
ago of a flint implement in association with the bones of extinct 
mammals at Lawford. This implement had been exhibited at 
the time to the Geological Society, but had disappeared after the 
meeting. Mr. Lloyd and Mr. Wilson briefly replied. 
Chemical Society, January 20,—Professor Williamson, 
President, in the chair. ‘The following gentlemen were elected 
Fellows :—T. Bell, A. Bird, G. R. Hislop, E. Lapper, H. 
Seward. The first paper read was a note on the absorption of 
mixed vapours by charcoal, by John Hunter, M.A., Queen’s 
College, Belfast. The author some time ago, published in 
the Fournal of the Chemical Society (May 1868), the results 
obtained by absorbing the mixture of two vapours by means of 
cocoa-nut charcoal. He found that the absorption was increased 
when one of the vapours was at a temperature near to its point 
of condensation ; and he explained the phenomenon by assuming 
that when a fragment of charcoal is introduced into a mixture 
of two vapours, the one which is nearest to its point of conden- 
sation is first absorbed, and this, in its condensed state, aids the 
absorption of the other. According to this view, a succession 
of condensations is going on. The theory is strikingly illustrated 
in experimenting with a mixture of water vapour and ammonia 
gas—obtained by heating an aqueous solution of ammonia of spec. 
gray. 0°88—when the mixture is much more largely absorbed than 
either the gas or the vapour separately. The mean ofa set of experi- 
ments made at 100° C and 706'2 mm. pressure was 316°6 vols. of the 
mixture absorbed by one vol. of cocoa-nut charcoal. The Presi- 
dent remarked that the results of the experiments were entirely 
in accordance with what was expected on theoretical grounds. — 
The next communication was ‘‘On the composition of iron 
rust,” by Dr. Crace Calvert. The author had lately occasion to 
analyse rust obtained from two different places—from the outside 
of the Conway Bridge, and from Llangollen, North Wales—and 
he found both specimens to be composed as follows :— 
Sesquioxide of iron . . . . 92°900 
iRrotoxideoficon! Set) OF D777 
Carbonate of iron . ae OLOL7, 
Carbonate oflime. . . . 0°295 
SWE o 6 0 Ceo. OF oo oe OREN 
ENTINOUE 5 fo og og 6 6  weKees 
100°000 
This result induced the author to inquire to which of the con- 
stituents of the atmosphere the formation of rust is chiefly due. 
With the view of ascertaining this, carefully cleaned blades of 
steel and iron were put into tubes filled respectively with 
oxygen, oxygen and a little carbonic acid, oxygen and moisture, 
&c. The blades were introduced into gas-collecting cylinders, 
which were then filled above mercury with oxygen, &c. But 
this proved to be an unsatisfactory method, inasmuch as always 
some globules of mercury remained adhering to the iron, 
whereby a galvanic action was produced which of course 
induced a rapid oxidation. To avoid this the tubes were filled 
simply by displacement of atmospheric air. The blades were 
then left exposed to the action of the different agents for a 
period of four months. The results were as follows :— 
Blades in dry oxygen .. .. No oxidation. 
ioe OISE +. .. Out of three experiments only 
in one a slight oxidation, 
», dry carb. acid . . No oxidation. 
SSR OLS Camas . . Slight incrustation of a white 
colour. (Out of six experi- 
ments two did not give this 
result. ) 
5, dry carb. acid and 
Ose “oa 64 
>» moist carb. acid 
and oxygen... .. 
>, dry oxygen and 
ammonia .... 
» Moist oxygen and 
ammonia .. .. 
No oxidation. 
Most rapid oxidation. 
No oxidation. 
No oxidation. 
These facts led the author to assume that it is the presence of 
carbonic acid in the atmosphere, and not oxygen or water 
vapour, which determines the oxidation of iron. The author 
next investigated the behaviour of iron in water in which suc- 
cessively oxygen, carbonic acid, a mixture of the two gases, &c., 
were conducted. He immersed only a part of the blade in the 
water. The results were analogous to those above mentioned, 
inasmuch as the most rapid oxidation took place when a mix- 
ture of oxygen with carbonic acid was introduced into the 
water. The action commenced immediately, and in a short time 
a dark precipitate covered the bottom of the vessel. Now the 
oxidation in this case was not due toa fixation of the oxygen 
dissolved in the water, but to oxygen liberated from the water 
by galvanic action ; the occurrence of large quantities of hydrogen 
above the liquid in the bottle proved this sufficiently. A striking 
evidence in favour of the supposition that the iron is oxidised 
through the decomposition of the water, is to be found in the fact 
that when a bright blade was introduced into distilled water which 
had previously been deprived of all its absorbed gases by long- 
continued boiling, it became, in the course of a few days, covered 
here and there with rust. The spots upon which the rust ap- 
peared proved to be impurities in the iron. It is obvious they 
induced galvanic action, just as a mere trace of zinc placed 
on one end of the blade would establish a voltaic current.— 
Finally, Dr. Calvert investigated the state of iron in alkalies, 
and he discovered that not only the solution of caustic soda, but 
that of the carbonate of it as well, protects iron against any 
oxidising action, 
Linnean Society, January 20.—Prof. Babingion read a 
paper, being a revision of the Flora of Iceland. He gave an 
extempore sketch of the country, its climate and character, and 
then read the introductory part of his paper containing an his- 
torical account of what had been done towards ascertaining the 
vegetable products of the island. It appears there are about 
450 species of phanerogamous plants (the exact number at pre- 
sent recorded is 467), of which only about 60 are not natives of 
Britain. None are peculiar to the island ; all the remainder, 
with three exceptions, are to be found on the European conti- 
nent, chiefly in Scandinavia ; the three arctic plants not other- 
wise known as European are Gentiana detousa, Pleurogyne rotata, 
and £fpilobium latifolium. No woods are now to be found in 
the country, although some existed recently ; they have been 
destroyed by the carelessness of the inhabitants. Now that 
more care is taken of their remains, it is expected that they will 
again spring up. The trees were all birch, nor is there any 
trace of the former existence of pine or other trees. Extensive 
woods of dwarf birch-trees are found in several places, and some 
fruticose willows exist, especially an abundance of S. /anata. 
No grain of any kind is grown on the island. 
Zoological Society of London, January 13.—John Gould, 
F.R.S., V.P., in the chair. The secretary called attention to 
certain additions to the society’s menagerie during November 
and December last, amongst which was particularly noticed a 
rare American monkey (/%thecia ouakari) from the Rio Negro, 
deposited by L. Joel, Esq., C.M.Z.S.—A letter was read from 
Lord Lilford, F.Z.S., relating to the exact locality of a speci- 
men of Otus capensis, lately living in the society’s gardens.— A 
letter was read from Dr. A. Ernst, of Caraccas, C.M.Z.S., con- 
taining some notes on animals recently obtained in the vicinity 
of that city.—The Rey. H. B. Tristram, F.R.S., exhibited a 
pair of tawny eagles (Aguila mevioides) obtained near Etawah, 
N.W. India, by Mr. W. G. Brooks, C.E., being the first 
authentic examples of this species received from that country. 
—Mr. Swinhoe exhibited and made remarks on some skins of 
tigers and leopards from various parts of China.—Mr. Gould 
exhibited a new and very remarkable pigeon, supposed to be 
from New Guinea, which he had recently described under the 
name Oz:diphaps nobilis.— A communication was read from Mr. 
Henry Adams containing descriptions of a new genus, and of 
eighteen new species of land and marine shells from the Red 
Sea, Hainan, and other localities: —A communication was read 
from Dr. Cobbold containing the description of a new generic 
type of Entozoa, discovered in a specimen of the Aard-wolf 
(Proteles cristatus), which had recently died in the menagerie. 
To this were added remarks on the affinities of this Entozodn, 
especially in reference to the question of parthenogenesis. —A 
communication was read from Mr. Morton Allport, F.Z.S., con- 
taining a brief history of the introduction of the salmon (Samo 
salar) and other Sa/monide to the waters of Tasmania.—Dr. 
Murie read a paper containing additional memoranda on irregu- 
larity in the growth of salmon. Dr. Murie’s observations were 
founded principally upon specimens hatched and reared in the 
society’s fish-house, 
