338 
sion over Paris and a large tract of the country from the 4th up 
to the 26th, without any intermission. Neither sun, nor stars, 
nor moon were visible for an instant during that leng:hesed 
eriod, 
, The prevailing opinion among meteorologists was that the 
nebulosity was formed by a mass of snow suspended in the atmo- 
sphere. 
Although the notion was generally accepted, I opposed it, in 
my contributions to Z’£lectricité, remarking that if such 
were the case, snow or at least water should have fallen in Paris 
and vicinity where the dryness was complete from the apparition 
of this remarkable nebulosity. But being unable to settle the 
controversy without actual observation, I ascended in a balloon 
from Ia Villette Gas Works on January 25 at 2h. 35. p.m. I 
found my anticipations were quite correct, as not a single flake of 
snow was seen by me or by M, Anatole Brissonet, a young 
gentleman who was‘ assisting me by manceuvring the balloon. 
But I was quite deceived in the thickness of the cloud, which 
did not exceed 300 metres, although it rendered the sun perfectly 
invisible, and I had written it ought to be numbered by 
thousands. 
The earth was lost sight of gradually, and was perfectly in- 
visible at 270 metres, but the sun was shining in all its glory at 
580 metres, with blue sky. The cloud was not so blinding as 
usual when it is composed of condensed vapour, as the thermo- 
meter and barometer could be read with perfect accuracy in the 
centre of it, and the lower part of the balloon was entirely 
visible at a distance of about 4 or 5 metres, but the equator was 
lost in whitish smoke perfectly impenetrable to sight. This nebu- 
lous matter appeared perfectly homogeneous, and I could see no 
trace of any crystalline matter, but an unexpected observation 
proved that it was formed of minute solidified atoms of water in 
a real microscopic state of division. 
When we emerged from the cloud gently and slowly, I 
stop the throwing out of any ballast in order to remain in 
close vicinity of its surface. M. Brissonet and I observed 
carefully what was occurring around us. The heating effect 
of the sun was in some respect destroyed by the radiation 
towards the cloud, which was at a temperature of 5°C, So we 
were floatng at a level almost perfectly equal, in an air at 
a temperature from - 2° to —3°. The air at the surface of the 
clouds was perfectly calm, but at a few metres upwards it was 
moving north-north-ea-terly at a rate of eight miles an hour. 
The consequence was tliat we we were towed by the globe, and 
feeling keenly a cold current sweeping over our faces. We had 
uncoiled our guide rope, the length of which was 60 metres, and 
the end of which was consequently immersed in the cloud and 
dragged into it. To our intense surprise, and I may say delight, 
we perceived that this part was quite loaded with hoar frost, 
which had precipitated regularly by series of hairs a few milli- 
metres long. These accumulations during a sweep which lasted 
for an hour, and a distance of about eight miles, are coasistent 
with the fact previously stated, that no deposit was visible during 
our ascent, which had been very slow indeed. My calculations 
show that our vertical velocity was not exceeding 30 metres per 
minute, which is only one-eighth of our horizontal velocity, con- 
tinued during six times longer. In our descent, which was rather 
quicker, but not to a great degree, the sweeping may have accu- 
mulated the frost rime on the bottom of the car, which it could 
not have been easy to observe, and consequently I cannot state 
what occurred, but not a single crystal was deposited on our 
ropes during that period. 
I have been unable to procure Scoresby’s Sketches of the 
Polar Regions, but. only a review by Arago, who says (ix. 
P- 357, 10, et seg.) : ‘The ‘* frost-rime ou fumée-gelée est un phe- 
noméne particulier des ces regions de la terre ou le froid est de 
longue durée, dont une vapeur dense! qui est dans un état com- 
plet de congelation. . . . Les parties extrémement deliées dont 
le frost-rime se compose s’attachent & tous les corps vers les- 
quels le vent les pousse, et y forment quelque fois une croiite de 
plus de 3 centimétres d’epaisseur, herisse de longues files pris- 
matiques, ou pyramidales li pointe dirigée du cd:é du vent.” 
It seems to me that the constitution of cirrus clouds seems to be 
explained by these properties of /rost-rime clouds, These minute 
crystals, which can remain for an indefinite period suspended i. 
the air, are, properly speaking, the maveries nivei, but not nives 
i~sa- It is by motion, either vertical or horizontal, that they are 
changed either into hoar-frost or snow, according to circum- 
stances, W. DE FONVIELLE 
* I suppose that Scoresby is speaking of optical density. 
NATURE 
[ Fed. 9, 1882 
Researches on Animals containing Chlorophyll 
Mr. PATRICK GEDDES appears to have been anticipated in 
most of the points set forth in his paper on Further Researches 
on Animals containing Chlorophyll, published in NATURE of 
January 26 last, by Dr. Brandt, of Berlin, who, in a paper 
read before the Physiological Society of Berlin ‘on November 
11 last, and published in the Proceedings of the Society on 
the ‘‘Symbiosis of Lower Animals with Algz,” describes 
the cultivation, after removal from the bodies of the various 
animals affected by them, of the well-known yellow and 
green chlorophyll-containing bodies, their development of starch 
grains, and their successfol artificial implantation into the 
bodies of fresh hosts previously free from them; this latter 
being an important fact apparently not known to Mr. Geddes. 
Dr. Brandt further names the species of algz in question under 
two genera, Zoochlorella and Zooxanthella, and gives to the 
peculiar physiological relations of mutual advantage between 
the plants and animals the term ‘‘symbiosis*” Mr, Geddes 
appears not to have scen this paper of Dr. Brandt, since he 
merely refers to some of his earlier papers on the same subject, 
but it is important. Dr. Brandt’s claims in the matter should 
not pass without notice in Nature. I have not seen Dr. 
Brandt's original paper, but only an abstract published in the 
Naturforscher of January 14 last, from which I take the infor- 
mation given above. H. N. Moseley 
The Movements of Jupiter's Atmosphere 
In NATurE, vol. xxv. p. 213, Mr. Darwin describes the 
bands on Jupiter as ‘‘ due to the trades and anti-trades” set in 
m tion by the action of solar radiation on the solid body of the 
planet as are the trade-winds of the earth. Many other eminent 
astronomers still appear to accept this time-honoured explanation 
of the phenomena, 
Have they reflected on the revelations supplied by the low 
specific gravity of Jupiter? There is no form of matter with 
which we are acquainted that could exist at a mean density of 
about one-fourth of that of the earth, while subject to the 
enormous pressure due to the mass of Jupiter, unless it were 
sufficiently hot to render the formation of a solid crust on its 
surface quite impossible. In order to attribute terrestrial 
solidity to either Jupiter, Saturn, Uranus, or Neptune we must 
invent a new kind of matter as infusible as platinum, and far 
lighter than hydrogen, or endow it with absolute incompressi- 
bility. 
These planets, if composed of any of the chemical elements 
or compounds known to us, can only retain their low density 
under the enormous pressure of their masses by the agency of 
proportionately counteracting heat-repulsion. j|At and about 
their centres this may be so far overcome by the superincumbent 
pressure as to produce solid nuclei, but these must be very small 
in proportion to the mass of the planet. 
Assuming the existence of such a central nucleus of Jupiter 
surrounded by a great fluid envelope, how will it be affected by 
the gravitating reaction of the satellite, supposing the compres- 
sion to give it a specific gravity exceeding the mean specific 
gravity of its envelope? 
It will obviously perform an eccentric rotation, or reeling, 
within the envelope. This motion must be very irregular and 
complex, owing to the different periods and the varying relative 
positions of the satellites; but the varying resultant of their 
gravitation forces will have one element of constancy, viz. a 
close coincidence with the plane of the planet’s equator. 
The effect of such internal reeling upon the surrounding 
gaseous mass explains far more efficiently than any possibility of 
solar radiation, the disturbances indicated by the ever-changing 
belts and spots of this planet; and also the greater rotatory 
velocity of the equatorial spots, described by Mr. Denning in the 
above-named number of NATURE, p. 225. 
The correspondence of these with the varieties of rotation of 
the different parts of the solar surface observed by Carrington, 
is well worthy of note, and admit of similar explanation ; plane- 
tary reaction in the case of the sun taking the place of the 
satellite reaction on Jupiter. In my essay on ‘‘ The Fuel of the 
Sun” I have worked out other consequences of this reeling of 
the solar nucleus and their analogues in the greater planets. 
Stoneb-idge Park, January 26 W. MATTLEU WILLIAMS 
“The Lepidoptera of Ceylon” 
Mr. F. Moore in no way betters the case against him by his 
Jetter printed in NATURE, vol. xxv. p. 79. The name of George 
