516 
similar vibrating condition, giving rise to similar colours and 
similar tastes. A study of the carbon compounds yields as con- 
clusive evidence. The alcohol bodies, such as mannite, grape- 
sugar, glycerine, glycol, are sweet. They possess a certain 
common molecular structure and a compound radical, CHy.OH. 
Associated with this radical is the taste called sweet, just as 
are associated with it many chemical and physical proper- 
ties. Common alcohol is tasteless, but it is monatomic, all the 
polyatomic alcohols having a sweet taste. The organic acids, 
too, have a radical, CO.OH, with which seems to be associated 
their acid properties and the power of producing a special taste. 
Now it is certain that compound radicals, like elementary 
substances, vibrate in a definite way, however they are com- 
bined. A coloured acid like chromic and picric acid forms a 
class of coloured salts. Ammonia viewed in quantity shows 
characteristic absorption-bands ; replace an atom of hydrogen 
by ethyl or methyl, and the same bands are to be observed, 
shifted, however, slightly towards the red end of the spectrum. 
We see, then, in the carbon compound the radical vibrates, 
modifies light passing through it in a definite way, and affects 
the sensorium by causing the production of a definite sensation 
of colour. So too it can produce a definite taste sensation. I 
do not hazard an opinion as to how the molecule stimulates the 
end-organs in the tongue. Too little is known about the stimu- 
lation of the retina by light. Whether or not in both cases it 
is mechanical, one cannot say. As to its being chemical action, 
it may well be asked, What is this? Chemical action itself may 
perhaps be most satisfactorily interpreted by the use of a mecha- 
nical hypothesis. Much has yet to be discovered as to the exact 
relationship between vibration and taste sensation. That this 
relationship exists, is all the author wishes to prove. When 
spectroscopic investigation of the invisible spectrum is more 
advanced, what Helmholtz has done for sound may also be done 
for taste, and we may know the exact vibrational counterpart of 
a taste quality as we know it already of the sound of a violin- 
string. 
PARIS 
Academy of Sciences, September 13.—M. Emile Blanchard 
in the chair.—Experiments on the electrical conductibility of 
gases and vapours, by M. Jean Luvini. A series of experiments 
are described, which have led the author to the general conclu- 
sion that, under all pressures and at all temperatures, gases 
and vapours are perfect insulators, and that they cannot be 
electrified by friction either with themselves or with solid or 
liquid bodies. Crucial tests were applied to air saturated with 
the vapour of water at temperatures ranging from 16° to 100°C. ; 
to hydrogen and carbonic acid not dried, but just as they left 
the bath generating them ; to the vapour of mercury at 100° C. ; 
the vapours of sal ammoniac ; air heated by live embers or the 
flame of a candle; the fumes of sugar, camomile, incense, &c., 
none of which vapours gave the least indication of conductibility. 
Hence to suppose, as is generally done, that very rarefied gases, 
or gases at very high temperatures, are conductors, is a mistake 
due to confusion between resistance to disruptive and conductive 
discharges. Thus Masson has shown that at like potential the 
distance of the disruptive discharge in the air is twelve or 
thirteen times greater than in water, which simply means 
that the resistance of water to the disruptive discharge is greater 
than that of air, not that air is a better conductor than water. 
Henceforth physicists will have to reject all theories regarding 
the electricity of machines, the air, or clouds, in which moist air 
is assumed to be a conductor, or in which gases and vapours 
are supposed capable of being electrified by friction.—Quanti- 
tative analysis of the dry extract of wines, by M. E. Bouilhon. 
In order to shorten the ordinary tedious process, some chemists 
separate the liquids by means of porous bodies increasing the 
surface of evaporation. But this method leads to falla- 
cious results, numerous experiments showing that all increase 
of the surface lowers the weight of the residuum to a 
very considerable extent, in consequence of the evapora- 
tion of a portion of the glycerine. Thus a litre of claret 
yielded 22°4, 22°0, and 21°2 grammes of sediment according 
to the various forms and sizes of the vessels employed in the 
process.—On /ecampia erythrocephala, anew species of Rhabdo- 
cele, parasitic and nidulating, by M. A. Giard. This species, 
which is very common on the coasts of Fécamp and Yport, is 
shown to differ considerably from Graffilla and the different 
genera of Rhabdoccele hitherto described. It appears greatly 
to resemble a parasite discovered by Lang in the foot of Zethys 
fimbriata, and a more complete study of this Mediterranean type 
NATURE 
[Sepz. 23, 1886 
Sa 
will no doubt show that, like the parasite here described, it also” 
secretes a cocoon.—Researches on the circulatory apparatus of 
the Ophiures, by M. R. Koehler. The circulatory system of these 
organisms, as here described, appears to be very analogous to_ 
that of the Echinidze, as already revealed by previous investiga 
tions of the author and M, Prouho. Both groups present the 
same structure of the madreporic gland, the same relations o 
this gland, on the one hand with the periphery, on the other 
with a peribuccal ring ; two peribuccal rings throwing off two 
branches in the same directions ; lastly, the absence of aboral 
circle.—On the heart, digestive tube, and reproductive apparatus 
of Amarecium torguatum (a Compound Ascidian), by M 
Charles Maurice. _ In this paper the author determines the true 
physiological functions of some of the organs already obsenmagy 
by Seeliger, Von Drasche, and Della Valle in other species o 
Ascidians.— On the annual movement of the barcmeter in Euro- 
pean Russia, by General Alexis de Tillo. While the yearly 
oscillations of the barometer in Siberia may be figured by a 
curve of somewhat simple type, those of European Russia are 
shown to be of a much more complicated character. From the 
numerous records published by the St. Petersburg Central Phy- 
sical Observatory, the author has deduced the mean monthly 
readings for eighty meteorological stations in this region, ani 
these data have enabled him to determine the mean type of the 
annual barometrical curve for the centre of European Russia, 
As it advances eastward in the direction of Siberia and Central 
Asia, this curve loses its secondary maxima and minima, while 
on the other hand its amplitude increases gradually. 
BOOKS AND PAMPHLETS RECEIVED 
“© Marion’s Practical Guide to Photography,”’ new edition (Marion and 
Co.).—‘‘ Die Angiospermen des Bernsteins,”’ Zweiter Band, by Dr. 
Conwentz (Danzig).—‘' Verhoffentlichungen der Grossherzoglichen Stern- 
warte zu Karlsruhe,” Zweiter Heft, by Dr. W. Valentiner (Karlsruhe).—*‘ Pro- 
ceedings of the Royal Society of Queensland, 1885,” vol. ii. parts x and 2 
(Brisbane).—‘‘ Boston University Year-Book,” vol. —‘* Results of Rai 
and River Observations made in New South Wales during 1885,”” by H. C. 
Russell (Sydney).—‘ Letters on Sport in Eastern Bengal,” by F. B. Simson 
(Porter).—‘‘ Nyt Magazin for Natur ridenskaberne,” 12 parts (Christiania) 
—‘* Mountaineering below the Snow-Line,” by M. Paterson (Redway). 
CONTENTS 
Exterior Ballistics’: 2 i jn-) ie) eileen mate 
Our Book Shelf :— 
‘*Tllustrations of the Indigenous Fodder Grasses _of 
the Plains of North-Western India.”—Prof. W. 
ISTE po aS OPO oO goo oo 5 Oo 
Start’s ‘‘ Exercises on Mensuration” ...... . 
Miss Peabody’s ‘‘ Lectures in the Training Schools 
for, Kindergartners) <1.) cient 
Vivarez’ ‘‘ Mouvement scientifique et industriel en 
1885. Causeries scientifiques” ...... 
Letters to the Editor :— 
British Association Sectional Procedure.—Prof. 
Oliver’ Lodge. 2 wos, .'s, Ble Ws ot ee) pe 
The Geological Age of the North Atlantic Ocean.— 
Prof. Edward)Hull) F.R:S.2 . .) o.0:seneeen 
Earthquake atSea—H. Mohn ......... 496 
Peripatus.—Prof. John C. Branner. . . 497 
The Recent Earthquake in Greece. By Capt. W. 
J. L. Wharton, F.R.S.; Capt. L. Aquilina. . . 
The Total/Solar Eclipse. of 1886 = =~) =) eee 
NCS oe o 6 6 oe O66 
Our Astronomical Column :— 
Photographic Determinations of Stellar Po-itions . 
GoreisiNovai@rionisy mes euret ec rel elie 
Heliometric Observations of the Pleiades ..... 
Gould’s Astronomical Journal... . +. .+... 
Astronomical Phenomena for the Week 1886 
September 26—Octoberi27) 2) 4. ee 
The British Association :— 
Section G—Mechanical Science—Opening Address by 
eke je No. (=> Jo.) sau nly eine 
Sir James N. Douglass, M.Inst.C.E., President 
Of the Section’ yy etre) Giles fey cis) ol nn 
INS tt Geol CG sOsG HeGeeroes > o> 
Section A—Mathematical and Physical Science . . 507 
Section B—Chemical Science ....-...... S51 
Section C—Geology . toe ue ee eee 
Societies ‘and’ Academies.) 2 2.) -) -) <0) 0-) <n ee 
Books and Pamphlets Received ......... 
