NATURE 
22! 
Helmholtz and Thomson, It is to be hoped that the 
latter will soon complete his papers on Vortex Motion 
and give them to the world. But why does no one else 
work in the same field? Has the multiplication of 
“symbols put a stop to the development of ideas ? 
OUR BOOK SHELF 
Natural History Transactions of Northumberland and 
Durham. Vol. 1V. Part II. (Williams and Norgate.) 
Tuts volume of upwards of 250 pages confirms the repu- 
tation already attained by the Tyneside Naturalists’ Field 
Club, as being one of the most efficient provincial scientific 
societies inthe kingdom. Nearly all the papers are of real 
and permanent value, and it is to be hoped that ere long 
some means will be found of bringing the work of this and 
- similar societies before a larger public than is likely to be 
_ reached by “ Transactions,” which are seldom seen by 
any but the members or their friends. A large part of 
_ the volume is devoted to the excellently compiled Me- 
_teorological Reports for 1870 and 1871, by the Rev. 
R. F. Wheeler, M.A. There is here much valuable ma- 
terial, more interestingly and artistically put together 
than such reports usually are. Mr. T. J. Bold con- 
tributes a well-arranged catalogue of 151 species of He- 
miptera-Heteroptera of Northumberland and Durham. 
_ Mr. Bold contributes besides many valuable notes on 
various other kinds of insects found in the district so well 
worked hy the Tyneside society; Mr. Bold deserves the 
highest credit for the quantity and quality of his work. 
Messrs. A. Hancock and T. Atthey describe a con- 
siderable portion of a Mandibular Ramus of Axnthra- 
cosaurus Russelli (Huxley), found in the new ironstone 
shale of Fenton ; they also add some notes on Loxomma 
Almanni (Huxley), and on some additional remains of 
Archichthys Suicidens (Hancock and Atthey), recently 
found at Newsham. The same gentlemen contribute a 
few remarks on Difterus and Ctenodus, and on their rela- 
tionship to Ceratodus Forstert (Krefft). A well-arranged 
list of the non-parasitic marine Cofefoda of the north-east 
coast of England is Mr. G. S. Brady’s contribution to the 
volume. The President’s address, consisting mainly of a 
_ graphic account of the numerous club excursions during 
_ 1871, is the last paper in the volume, one of the most valu- 
able features of which is the numerous and carefully 
executed lithographs which are appended. Nearly every 
paper is illustrated. Altogether it is a thoroughly satis- 
factory specimen of work. 
LETTERS TO THE EDITOR 
t The Editor does not hold himself responsible for opinions expressed 
by his correspondents, No notice is taken of anonymous 
communications. ] 
Phosphorescence in Fishes 
THE only reliable observations of active phosphorescence in 
fishes during life, known to the writer, are the following, to 
which, perhaps, may be added, the somewhat obscure observa- 
tions on Hemiramphus lucens, communicated to G. Cuvier by 
Reinwardt :— 
x. The observations of the two Bennetts (“ Whaling Voyage” 
and ‘Gatherings in Australia”) on a small luminous shark 
(Squalus fulgens : Isistius brasiliensis, Q.G.). (Perhaps also ob- 
served by Giglioli.) Aae'g 
2. The observations of J. Bennett on the luminosity of Scofe- 
dus stellatus (l.c.). ; 
__ 3. The luminosity of the head of Astronesther niger observed 
_ by Reinhardt (Videnskab. Meddel. f.d. naturhist. Forening : 
of certain enigmatical organs in the skin of these fishes as their 
“luminous phosphorescent organs.” 
In Mr. Saville Kent’s very sensible remarks on the phospho- 
rescence (erroneously ascribed to several other fishes), in vol. 
vii. p. 47 of NarTurRE, I find a statement that startled me 
alittle, viz., that ‘‘it has been proved beyond doubt that certain 
fish, Cyclopterus lumpus, for instance, do possess highly luminous 
properties” (during life, of course, or Mr. S. K. would not have 
mentioned it at all in this connection). I think that the observa- 
tions regarding Cyclopterus lumpus, upon which this statement 
is based, are unknown to other zoologists than the writer, and 
that they would be much obliged to Mr. S. K, for a reference 
to his source of information. 
Movements of the Earth’s Surface 
Ir is, I believe, commonly supposed by geologists that the 
movements of the surface of the earth are caused by the refri- 
geration and contraction of the interior. But since the glacial 
epoch the surface of the earth has become warmer ; conse- 
quently since that time a heat wave must have been passing from 
the surface towards the centre ; and consequently since that time 
no refrigeration nor contraction of the interior can have taken 
place. If, therefore, movements of the earth’s surface were due 
to this cause only, no such movements should have taken place 
since the glacial epoch. F, W. Hutron 
Wellington, New Zealand, Nov. 10, 1872 
Meteor Observed at Mauritius 
ON Noy. 7 last, about 7 o'clock. p.m., I saw the most beau- 
tiful meteor fall that I ever remember observing in my life, 
My face was turned in the opposite direction, but an unusually 
brilliant and sudden flash of light, above the brightness of the 
moonshine, caused me to turn suddenly round in the direction 
the effulgence came from, and I saw a very large meteor majes- 
tically falling through the distance, seemingly of about eight or 
ten yards. I am not much of an astronomer, but I think it 
must have fallen, apparently, from some point in Aquarius, 
What particularly struck me in its appearance was that it was 
beautifully distinct, and round as the full moon, but seemingly 
about the 4th of a diameter larger. I ought, perhaps, rather to 
compare it to the moon at the end of her first quarter. [See 
p. 231 of this Number.] 
A quarter of its disc only was luminous and brilliant, while the 
upper three-quarters emitted no luminosity, being ofa dull, dusky, 
stone-brown colour. Here the circular outline was perfectly 
distinct, while the brightness of the lower limb took away all 
distinctness of outline there, making it appear slightly more 
prominent, besides throwing beyond the outline of the meteor 
itself a beautiful soft, steady, very bright radiance of a bluish 
white tint, which illuminated momentarily the whole heavens, 
Tt was observed by other people, and one person described to 
me having seen a similar meteor fall about this time last year, 
the disc appearing ‘“‘about the size of a saucer,” entirely 
luminous, but then no moon was shining. 
W. WRIGHT 
Moon’s Surface 
May not the white, telescopic appearance of the moon’s sure 
face, resembling snow in many parts, be explained by the fact 
that the extinct volcanoes of our satellite are covered with crystals 
of salt ? 
Any person who is accustomed to view the moon through a 
telescope must, I think, have been struck with the dazzling snow- 
white appearance of the mountains. May not an explanation of 
this be deduced from the experiences gained by the last eruption 
of Vesuvius ? 
“ One of the most curious phenomena observed is the power of 
burning lava to retain an enormous quantity of water and salt, 
which it does not allow to escape till it beginstocool. . . , 
The formation of salt is shown generally over the whole stretch 
of lava emitted in 1872. Soon after the surface cools it is covered 
with a light crust of salt.”—See NATURE, vol. vii. p. 2. 
Is it not, therefore, probable that the numerous lava beds of 
the extinct volcanoes in our satellite may be coated with salt, 
bleached to the-whiteness of snow ? 
C, H. W. Mgruin 
British Consulate, Athens, Nov, 23 
