270 
NATURE 
[ Fan. 6, 1870 
into a sealed tube, and heated for 7 hours to 125°. The prin- 
cipal results of this reaction were hydrochloric acid, free iodine, 
and methylene iodide CH,I,. Now, remembering the fact, de- 
monstrated by Kekulé, that iodides, submitted to the action of 
hydriodic acid, undergo an inverse substitution, the reaction just 
described may be explained by supposing that the chloroform is 
in the first instance converted into iodoform, which is then con- 
verted into methylene iodide by the action of the hydriodic 
acid, thus— 
CHCl, + 3HI=CHI, + 3H], 
and CHI, + HI = CH,I, + I,. 
In other cases, the action represented by the second equation 
goes so far as to remoye all the iodine from the iodated product 
formed in the first instance, and convert it into the corresponding 
hydride. Such, indeed, is the case with compounds belonging 
to the aromatic series. Berthelot [Bull. Soc. Chim. (2) ix. 30] 
has shown that Julin’s chloride of carbon, or perchlorinated 
benzene, C,Cl,, is converted into benzene, C,H, when heated to 
280° with a large excess of hydriodic acid ; and Lieben finds that 
monochlorobenzene, C,H,Cl, heated to 235°, for 15 hours, with 
from three to five times its weight of hydriodic acid, likewise 
yields benzene. 
The action of hydriodic acid on organic chlorine-compounds 
appears, then, to exhibit two cases :—(1.) The chloride is easily 
converted into the corresponding iodide by double decomposi- 
tion, whereas the transformation of the iodide into the corre- 
sponding hydride is difficult, and takes place only at high tem- 
peratures. In this case, if the experiment is well conducted, an 
iodide is obtained without a trace of hydride. Such is the case 
in the action of hydriodic acid on the chlorides of the series 
C,H.,4,Cl. (2.) The chloride is attacked by hydriodic acid with 
difficulty, and only at a high temperature, whereas the conver- 
sion of the iodide into hydride takes place easily, and at a com- 
paratively low temperature. In such cases, as with the chlorides 
of the aromatic series, the product of the reaction is a hydride 
without any trace of iodide. In some cases, as that of chloro- 
form, intermediate products are obtained, only part of the iodine 
being removed by the inverse reaction. [Giornale di Scienze di 
Palermo, v. 130. ] 
SCIENTIFIC SERIALS 
THE Archives des Sciences Physiques et Naturelles for December 
I5, contains a paper by Professor Heer, on the Miocene Flora of 
Spitzbergen. ‘The writer gives a preliminary account of the fossil 
plants collected and sent to him by the Swedish Polar Expedition 
of 1868. The number of species found in the ‘Spitzbergen Ar- 
chipelago amounted to 131, of which 123 were phanerogamic, 
and 8 cryptogamic. Figures and a detailed description of these 
are promised to appear in the Memoirs of the Stockholm 
Academy. ‘The next paper is an extract of Thomsen’s Thermo- 
chemical Researches (taken from Poggendorff’s Avzalen), to 
which Marignac has appended some valuable comments. Prof. 
Marignac adds a paper of his own, on the influence of water 
on the double decompositions of salts, and on the thermal 
phenomena which accompany them. The author was induced to 
publish this preliminary memoir in consequence of the appearance 
of Thomsen’s results. He points out some interesting cases of 
retardation of chemical equilibrium, and intends to investigate 
them further. The rest of this number—the last of the year— 
is occupied by the usual Bulletin Scientifique, Meteorological 
Observations, and an index to the volume (xxxvi. N. S.) 
In Polli’s Annali di Chimica applicata alla Medicina for 
December, we observe, among other papers, a note on the action 
of hydric sulphate on iodides, by Dr. Vitali. It is generally. 
supposed that the action referred to terminates with the pro- 
duction of sulphurous oxide and iodine; but Vitali has noticed, 
in addition, the formation of hydric sulphide and sulphur—fresh 
instances, consequently, of the reducing energy of hydric iodide. 
In a paper on Ferric Albuminate, Peretti shows that albumen is 
capable of dissolving Ferric oxide. The filtered solution, if 
evaporated at a gentle heat, dries up to a rose-coloured pellicle, 
which can be again dissolved in water, and coagulates at 75°. 
Details are given as to some of the reactions of the solution. 
Bellini contributes an larticle on the therapeutic (pharmaceutical) 
formulae of sulphur. There are also several papers on dietetics, 
hygiene, and pathology, &c., taken from other journals, and an 
index to the volume, of which the present is the concluding 
number. 
Tue last two numbers of the Revue des Cours Scientifigues 
(Dec. 25, 1869, and Jan. 1, 1870), contain an elaborate paper on 
Vaccination, by M. Brouardel ; a translation of Dr. Bence 
Jones’s Croonian Lectures ; an account of Schimper’s Researches 
in Vegetable Palzeontology, by M. Ch.Grad ; and a lecture given 
by M. Bouchardat at the Paris Academy of Medicine *‘On the 
Mortality of Foster-children.” 
SOCIETIES AND ACADEMIES 
LONDON 
Geological Society, December 22, 1869.—Prof. Huxley, 
LL.D., F.R.S., in the chair. Messrs. Hopkinson, J. Sanders, 
and Jabez Church, C.E., were elected Fellows of the Society. 
The following communications were read :—1. ‘‘ On the Iron- 
ores associated with the Basalts of the North-east of Ireland.” 
By Mr. Ralph Tate, Assoc. Linn. Soc., F.G.S., and John S, 
Holden, M.D., F.G.S. The authors introduced their account 
of the iron-ores of the Antrim basalts, by stating that since 1790 
an iron band had been known in the midst of the basalt of the 
Giant’s Causeway, but that only within the last few years have 
further discoveries been made, which have developed a new 
branch of industry in the north-east of Ireland. The iron-ore 
of the numerous exposures was considered to represent portions 
of one sheet extending uniformly throughout the basalt and over 
a very large area. Indeed everywhere the iron band and its 
associated rock-masses present identical features, from which the 
authors deduced the following generalised section :—The under- 
lying basalt gradually passes upwards into a variegated litho- 
marge of about 30 feet thick, graduating insensibly into a red 
or yellow ochre or bole of about 5--6 feet in thickness, which 
passes into a dense red ochreous mass of about 2 feet, charged 
with ferruginous spheroids consisting chiefly of a protoxide and 
peroxide. The spheroids are of the average size of peas ; they 
increase in number and size towards the upper part of the band, 
and not unfrequently constitute that portion of it. The line of 
junction between the iron band and the overlying, and usually 
more or less columnar basalt, is in all cases well defined, and in 
a few instances exhibits decided unconformability. The authors 
discussed the several theories that may be suggested to account 
for the origin of the present condition of the pisolitic ore, and 
proceeded to point out what appear to have been the several 
stages of metamorphic action by which the pisolitic ore had been 
elaborated out of basalt. From field observations and chemical 
analysis, they have been led to consider the bole and lithomarge 
as the resultants of aqueous action in combination with acidu- 
lated gases, which, dissolving out certain mineral substances, has 
effected the decomposition of the basalts; and to assume that the 
bole underlying the iron band was a wet terrestrial surface, and 
that the subsequent outflow of basalt effected. by its heat, pres- 
sure, and evolved gases, a reduction of the contained oxides of 
iron into the more concentrated form in which they occur in the 
pisolite, the aggregation of the ferruginous particles being a result 
of the same actions. The ferruginous series, with interstratified 
plant-beds at Ballypalidy, was next described, and demonstrated 
to be of sedimentary origin ; the ferruginous conglomerate re- 
sulting from the degradation of the pisolitic ore, of which it is 
chiefly reconstructed, and of the underlying ochres. Many addi- 
tions were made to the list of plant remains from these beds ; 
and priority of discovery of plants in the Antrim basalts was 
accorded to Dr. Bryce, F.G.S. Mr. D. lorbes was not pre- 
pared to admit some of the theoretical conclusions of the authors, 
and objected to calling in metamorphism to account for all that 
was hard to be understood. He could not recognise the division 
of beds so similar in character into two classes. He wished to 
know, assuming that the iron-ore merely resulted from the de- 
composition of the basalt, what became of all the silica and 
alumina which constituted three-fourths of the mass. The origin 
of the pisolitic ores was in fact organic. In Sweden certaiu 
lakes were regularly dredged each year for the pisolitic ore still 
in course of formation by means of confervyoid algae. He there- 
fore regarded the whole of these beds as in a certain sense sedi- 
mentary, and though due to organic agency, yet still deriving 
their original mineral matter indirectly from the basalt. The 
basalt contained a considerable amount both of phosphorus and 
sulphur ; and if the ores had been derived directly from the 
basalt, both these substances would have been present in them. 
This was an argument against any direct metamorphism. ‘The 
presence of venadium afforded additional reasons for regarding 
these ores as formed in the same manner as bog iron and 
