452 Chronicles of Science. | July, 
calculated by Mr. W. A. Royers, from the Washington observations. 
They are fully given in the ‘Monthly Notices, R. A. S.,’ vol. xxiv. 
p- 126. 
From some calculations communicated by Herr Theodor Oppelzer 
to the Astronomer-Royal, and published in the ‘ Monthly Notices’ of 
the R. A. S., for April of this year, it appears that the identity of 
D’Arrest’s and Pogson’s planets can no longer be doubted. From 
the observations taken at Copenhagen, Berlin, and by Pogson himself, 
Herr Oppelzer has calculated a small Ephemeris. Astronomers will 
therefore, in future, regard Freia= Sappho. 
III. BOTANY AND VEGETABLE PHYSIOLOGY. 
M. Gris has made recently some experiments on the contents of the 
vessels of plants. He uses a liquid called the liquor of Fehling, which 
is usually employed for the detection of glucose. It consists of sul- 
phate of copper, soda-lee (solution of caustic soda), tartrate of soda 
and potassa, and water, in definite proportions, and it preserves its 
limpid character when in a state of ebullition. When you add to it 
in a boiling state a very small quantity of glucose, there is produced 
a red precipitate of oxide of copper, which, when examined under the 
microscope, is seen to consist of very minute particles coloured deep 
brown or almost black. If in place of glucose some drops of sap are 
allowed to fall into the liquid, you obtain the same red precipitate of 
oxide of copper. If you immerse in the liquid for some time thick 
pieces of the wood of the Chestnut, Beech, Poplar, or Cytisus, in 
early spring, and cut thin slices for microscopical examination, you 
will notice an abundant precipitate of oxide of copper covering the 
inner surfaces of the large vessels, so that their course in the thickness 
of the woody layers may be traced by visible reddish thread-like 
streaks. As the same precipitate is very abundant in the cells of the 
medullary rays, M. Gris concludes that the vessels called lymphatie, 
contain (in spring at least) a sap analogous or identical with that 
found in the cellular elements of the same branch, and that the pre- 
cipitate of the oxide of copper is probably determined in both by the 
presence of glucose. M. Gris thinks that the lymphatic vessels 
always contain liquid sap mixed with a more or less considerable por- 
tion of air. 
M. P. Dalimier has performed a series of experiments from which 
he concludes that the vessels in the course of formation in the young 
tissues of plants may conduct the sap, but when they are completely 
formed,—the epoch at which they receive the names of porous or 
spiral vessels, &c., their normal condition is to contain air ; they 
only contain sap in certain plants, and during a comparatively short 
time. 
M. Belhomme has made experiments on the pollen of plants belong- 
ing to the Natural Orders Liliacew, Musacere, Araceze, Amarylli- 
