The Sun.
London, England, 1856-08-14 00:00:00

SECTION 8.-CHEIIICAL SCIENCE.

The paper by Professor Bunsen' and Dr. H. E. Roscoe on
"Photochemical Researches," read yesterday, stated that
the method pursued by thorn in attempting to obtain a
measure of tho chemical action of light was to evolve a
mixture of hydrogen and chlorine by the decomposition of
hydro-chloric acid by a galvanic current. This mixture of
gases is sensible in a high degree. So far their experiment
was the same as Draper's ; but they soon found that by
using his method the results were incorrect, owing to his
machine leaving no regular pressure of the gas in it, and
also the mixture of the gases being variable in proportion.
By their method they eliminated these errors, so that they
found their machine give constant comparable results.
They also found that the chemical action varied inversely
as the square of the distance from the source of light.
Mr. WORSLEY also read a paper on Dr. Gaett's improve-
ments in making iron and cast steel. This process was
worthy of notice, it being one of the earliest attempts
made to introduce into England the principle of gas fuel
in a more perfect manner than has yet been effected. The
principle was to reduce and carbonise iron ores, such as
harmetic and other ore free from sulphur and phosphorus,
by passing gas produced in a generator through a column
of ores, supplying at the same time air enough, to burn a
portion of the gas in order to give the temperature neces-
sary to the reduction of the ore, and the carbonisation cf
the so reduced iron, and, secondly, b melt the produce in
a second furnace.

Dr. GILBERT read a paper on the products and constitu-
tion of wheat grain. 'Dr. Gilbert's paper contained the ro
sults of a large number of experiments made by him and
Mr. Lawes, during a period of several years, upon wheat
grown in this country as well as abroad. Dr. Gilbert
subjected the various coarse and fine varieties of flour to
analysis, and showed that the nitrogEin increased in pro-
portion as the sample was coarser and contained more bran.
The flour that contained least nitrogen was that which took
up least water in the process of bread-ma king, and an in-
teresting question arose as to the nutritive value of bread
containing much or no bran. Dr. Gilb3rt's opinion being
in favour of the latter, as far as working men are con-
earned, notwithstanding the theoretically higher value of
bread containing bran. Another interesting fact stated by
Dr. Gilbert was that the Black Sea wheat in Europe and
the Southern State wheat in America were far richer in
gluten than those from the northern latitudes, those from
Dantzic containing least gluten, while they stood highest
among bread-making grain. Die character of the gluten
seamed dependent in soma degree on its oily constituent;
and therefore the quality of the bread depends on the
maturation of the seed.
Dr. It. D. THOMSON' remarked that the value of bread
might depend on the state of hydration of the starch and
gluten ; but was doubtful as to the value assigned to the
n itritions qualities of starch, as the French chemists
proved that the starch was often left undigested.
. . . .

Dr. VOELCKER stated that he had arrived at similar ex.

perimental conclusions as Dr. Gilbert, but while he ac-
knowledged that starchy bread was mechanically the best,
he combated Dr. Gilbert's view, that this was the most
wholesome kind of bread for the working man. He traced
the phosphoric acid found by Dr. Gilbert in the bran to
phosphorus contained'as such in the gluten, Dr. Voelcker
having found this element in caseine and legumine.
Dr. ailing, J. H. Pearsall, Mr. Maskelyne, and Mr.
Worsley took part in the discussion that followed. After
Dr. Gladstone's paper some discussion took place as to the
attire of Chemical affinity, Dr. Oiling calling in ques-
tion the prevalent views on the subject, more especially
what has been called elective affinity. Mr. Maskelyne

supported the other side of the subject, agreeing, however,
with Dr. Gladstone on the necessity of a better system of
expressing the results of analyses.
SECTION C.—GEOLOGY.

The proceedings commenced this morning by two papers,
ono read by Mr. J. B. Jukes, on the alteration of clay slate
into mica schist and gneiss by the granite of Wicklow, &c.,
and the other by Mr. H. C. Sorby, on the microscopical
structure of mica schist. These papers were both on the
same subject, Mr. Jukes proving on a large scale the re-
sults that Mr. Sorby had deduced from microscopical exa-
minations. The next papers were by Professor Harkness, on
the jointing of rocks ; by Professor Rogers, on the origin
of saliferous deposits ; by Mr. Etheridge, on the igneous
rocks of Lundy and the Bristol District ; by Mr. Mushet,
description of an ancient miner's axe in the forest of Dean;
and by Mr. Baily on fossils from the Crimea. This was,
as might be expected, a most interesting communication
upon some fossils collected by Capt. C. F. Cockburn, of
the Royal Artillery, principally in the southern end of the
Crimea, many of the fossils having been obtained from the
trenches, others by Major Cook, Royal Engineers, and
Lieut.-Col. C. L. Cocks, Coldstreatn Guards.
Sir R. kluucHrsoN, in a few remarks on the subject,
stated that he hoped in future that when any expedition
was sent from England a body of scientific men would be
attached to head-quarters.

Mr. J. P. WOODWARD also made a few remarks on the
shells which had been described, showing the gradual filling
up of the communication between the Aral, Caspian, and
Black Seas.