NATURE 
[Mov. 10, 1870 



PITCHER PLANTS 
FFERENCE of opinion has been expresséd as to 
the nature and use of the l quid found in the so- 
D! 
called pitchers of various plants, such as Nepenthes, 
Rafflesia, and certain Orchidacezs. The popular idea that 
these curious receptacles collect pure water for the re- 
freshment of the thirsty in arid places, would seem to be 
set at rest, by a consideration of the fact that these 
plants grow in moist and marshy places. There would 
seem, moreover, to be some improbability that plants 
should secrete pure water. 
In this country, where these plants are grown under 
exceptional conditions, there is some difficulty in settling 
these questions experimentally. In such cases, extra- 
neous water often finds its way into the pitchers, so that 
several ounces may frequently be gathered from a single 
receptacle of Nepenthes, the greater part of which is 
accidental. 
In August last I had an opportunity of collecting the 
liquid from two flowers of Coryanthes, one of the Orchi- 
daceze, which had just opened, in one of the well-known 
stove-houses of Mr. Wilson Saunders. 
Though the quantity collected was small, atnounting 
only to about three cubic centimetres, or 1°18 cubic 
inches, an examination showed the following properties :— 
Clear and somewhat glutinous in consistence. Pos- 
sessed of a high refractive power, anda specific gravity 
of 1'062. 
Odour pleasant but faint, becoming more marked by a 
gentle heat. Neutral to test papers. Becoming milky, 
by concentration on the water-bath, it finally yielded a 
transparent gum, insoluble in alcohol. 
Oxalates produced no precipitate of lime, but basic lead 
acetate gave a curdy reaction. 
phuric acid blackened the liquid. 

Although the taste was not acrid, the mawkish flavour | 
would render it quite unpotable. 
This examination therefore proved the liquid to be 
something else than pure water. 
Too parts of liquid contained :— 
Water and volatile oils . 98°51 
Non-volatile residue. . . . 1°49 
100°00 
G. B. BUCKTON 

SPECTROSCOPIC OBSERVATIONS OF THE 
SUN 
ROF. C. A. YOUNG has obligingly sent me an 
account of his recent work, which is very rich in 
promise, as he tells me that he has now the dispersive 
power of 13 prisms of heavy flint, each with an angle of 
55. It is now some time ago since I announced to the 
Royal Society that over spots prominences, built up of 
different vapours, were sometimes observable by means of 
their lines, dyiyht and thin, overlying the thick absorption 
lines in the spot spectra. This observation is, I hold, a 
clear proof of the truth of the theory put forward by Dr, 
Frankland and myself, namely, that changes in spectra, 
notably the thickening of the lines, are due to pressure, 
and not to temperature ; for according to the theory of 
exchanges, the bright prominence must be hotter than the 
absorbing vapour which underlies it, and still the lines 
are thinner. 
Dr, Young has now observed these phenomena with 
exactly the same result. He writes to Professor Morton :— 
“I write to inform you that last Thursday, Sept. 22, 
about 11 A.M. Hanover mean time, 1 was so fortunate as 
to see the so lium lines D, and D,, reversed in the spectrum 
of the umbra of a large spot near the eastern limb of the 
sun. At the same time the C and F lines were also re- 
versed, but with the great dispersive power of my new 

spectroscope I see this so often in the solar spots, that it 
has ceased to be remarkable. 
“The figure gives the appearance of the sodium lines. 
In the umbra of the spot the D, line was not visible, but 
in the penumbra was plainly seen, as a dark shade, repre- 
sented in the figure. 
“Tam not aware that this reversal of the sodium lines 
in a spot spectrum has ever been observed before ; its 
reversal in the spectra of prominencés is not very unusual. 
A small prominence on the western limb of the sun, which 
was visible the same forenoon, presented all the following 
bright lines, viz. :* C, D,, D,, Dz, 1474, 4,, 8, 8, 1989'5, 
2001°5, 2031°, F, 2581°5, 2796", and / ; 15 in all. ‘ 
“In the spot spectrum the magnesium lines 4,, 6, and 
6, were not reversed, but while the shade which accom- 
panies the lines was perceptibly widened, the central 
black line itself was thinned and lightened.” 
Further, Prof. Young has succeeded in obtaining photo- 
graphs of protuberances on the sun’s limb, of which he has 
been good enough to forward me a specimen. They were 
obtained by attaching a small camera to the eye-piece of 
the telescope and opening the slit somewhat widely, using 
the hydrogen line near G. 
little thing amounts to nothing, because the unsteadiness 
of the air and the maladjustment of the polar axis of the 
equatorial caused the image to shift its place slightly 
during the long exposure of three-and-a-half minutes 
which was required, thus destroying all the details. Still, 
the double-headed form of the prominence is evident, and ~ 
the possibility of taking such photographs is established.” 
In a letter to myself Prof. Young adds :—“I should 
not have published so imperfect a success were it not that 
my engagement as a member of Prof. Winlock’s eclipse 
| party prevents me from following up the matter at pre- 
Concentrated hot sul- par P. . g uP P 
sent. The experiments were tried on the 28th, and on 
the 3oth the equatorial was taken down to be packed up 
and sent to the rendezvous, at Alvan Clark’s factory, 
| where all the instruments are collected and put in order 
previous to sailing.” J. NORMAN LOCKYER 

NOTES 
SINCE our last issue the Joint Committee of the Royal and 
Royal Astronomical Societies and the Council of the British 
Association have met to consider the question of the Eclipse Ex- 
pedition, and in consequence of these meetings Mr. Gladstone 
has been asked to receive a joint deputation to urge upon the 
Government the importance of the proposed expedition. The 
Joint Committee have appointed the Presidents of the Royal 
and Royal Astronomical Societies, the Astronomer Royal, and 
Mr. Lockyer to plead its cause; while the Council of the British 
Association will be represented by the President and officers of — 
the Association, Sir John Lubbock, M.P., and Dr. Lyon Play- 
fair, M.P. Up to the time of our going to press, however, no 
time had been fixed for the deputation to wait upon the Prime 
Minister. 
THE medals in the gift of the Royal Society have this year 
been awarded as follows:—The Copley medal to Dr. Joule ; 
the Rumford medal to M. Descloiseaux ; and the Royal medals 
to Prof. W. H. Miller and Mr. W. Davidson. 
Pror. Simon Newcomgs has arrived in this country from the 
United States Naval Observatory. His mission among us is to 
examine and report on the great Newall telescope. He will 
then proceed to Gibraltar to observe the approaching eclipse. 
ALL members of the British Association will be concerned to 
learn that Dr. Hirst feels called upon by the pressure of his 
new duties to resign the General Secretaryship of the Asso- 
ciation, an honorary post which he has long filled with the 
greatest advantage to Science, 

He adds :—“ As a picture, the © 
a 
