Nov. 10, 1881 | 
Perhaps the ability of some lizards to produce sounds such as I 
have here described may not be new to some of your readers. 
1, Burlington Road, W., October 31 FRANCIs P. PAscoE 
SEALS IN Lake Barkat,—A. H. Keane wishes to know 
what authority there is for the statement made by E. Reéclus 
(‘*Géographie Universelle,” vi. 741) that seals outwardly re- 
sembling the Phoca fetida of Spitzbergen are found in Lake 
Baikal ; also what theories have been advanced to explain the 
presence of these Cetaceans in a freshwater lake over 1300 feet 
above sea-level. 
Napies ZooLocicaL STarioN.—For the terms on which 
permission can be obtained to work at the Naples Zoological 
Station, W. B. should write to Dr. Anton Dohrn, Stazione 
Zoologica, Naples. 
MELAPTERURUS ELECTRICUS.—Keep it in an aquarium of 
fresh water, not too cold, 
Rev. J. F. T.—See the notice prefixed to our Correspondence 
Columns. 
CHARLES W, HarpInG.—You should communicate with the 
widow, 
SHA FROTH 
] N a letter written by my nephew, Mr. Ernest Gladstone 
of Aberdeen, describing the recent storms, he says : 
“When we got within a quarter of a mile of the sea we 
were astonished to see great flocks of foam, like snow- 
balls, flying in all directions. A little further on we came 
to cne of the large hollows in the links, and we saw a 
sight none of us had seen before; for the whole hollow, 
about 100 yards long and 50 broad, was one sea of slimy 
foam, of which a great part must have been about Io feet 
deep. This was tossing up and down as if it were the 
sea itself. The waves of water broke far out at sea, but 
great rollers of foam kept rolling in towards the links, 
making it impossible to come near the sea without 
wading up to your waist in foam for nearly a quarter of a 
mile, and occasionally meeting a foam-wave up to your 
neck.” 
There is nothing unusual in this phenomenon, except 
the large scale upon which it took place. Almost every 
visitor to the seaside during rough weather must have 
observed the formation of a persistent sea froth, which is 
often carried great distances by the wind. The account, 
however, recalled to my memory some observations on 
the cause of the phenomenon which I made last year at 
Ilfracombe. 
The white foam of a breaking wave, under ordinary 
circumstances, disappears almost as quickly as the 
small bubbles of entangled air can rise through the water 
and burst at the surface. It occurred to me that there 
must be something dissolved in the sea water which gave 
rise to the formation of the more persistent froth, and the 
broken and bruised sea-weed suggested itself to my mind 
as a probable source of sucha substance. A quantity of 
it was therefore gathered, allowed to stand for several 
hours, till in fact it had run down to a liquid, and then 
filtered from the dirt and organic dééris with which it was 
mixed. The clear water thus obtained gave a persistent 
froth, like that of beer, whenever it was shaken, and I 
subsequently found tht it contained a considerable 
amount of organic matter. There was no distinct indi- 
cation of anything albuminous. 
In order to ascertain whether this property was due to 
broken sea-weed, two bottles were filled with ordinary 
sea water. Into one of these was put freshly-torn pieces 
of those kinds of fucus and other marine plants which were 
found growing between high and low water-mark, and in 
the other were placed strips of healthy laminaria freshly 
gathered from the lower zone. The bottles were violently 
shaken for a few minutes. The first gave a foam which 
quickly disappeared, while the second produced a froth 
which would remain more than twenty-four hours before 
NATURE 
33 
all the bubbles broke. It may be observed in passing 
that this sea-froth, whether naturally or artificially pre- 
pared, becomes very iridescent on standing. 
It seems fair to conclude, therefore, that the formation 
of this persistent froth is due to the destruction of the 
sea-weed—not of that which is tossed about by every 
tide, but of the laminaria which is uprooted and torn by 
the waves only when the violent agitation of the sea 
reaches a sufficient depth. J. H. GLADSTONE 
OUR WINTER REFUGES—VENTNOR 
I? is now upwards of half a century since Sir James 
Clark’s classic work “On the Influence of Climate” 
in the prevention and cure of chronic diseases appeared, 
and among the more important results which followed its 
publication was the establishment of stations in this and 
other countries for meteorological observations, by which 
alone the climates of various sanatoria might be accu- 
rately compared. To Sir James is due to a great extent 
the merit of having placed the investigation of this im- 
portant department of practical meteorology on a sound 
basis. 
The late Dr. Martin of Ventnor was one of the most 
intelligent and active of the co-operating band of ob- 
servers whose services were enlisted in the inquiry. A 
valuable series of observations was begun by him in the 
end of 1839, in establishing which Mr. Glaisher kindly 
gave his assistance and advice. The observations have 
since been carried on uninterruptedly, and they are 
evidently, particularly those of temperature and rain- 
fall, of such a quality as quite to meet the objects aimed 
at. The results are presented and summarised in a just- 
published volume*™ by Dr. Whitehead with ability, in their 
bearings on the climatology of Ventnor. 
The Isle of Wight occupies a high place as a favour- 
able and commodious residence throughout the year for 
a large class of invalids, owing to the variety which it 
presents in point of elevation, soil, and aspect, and to the 
configuration of its hills and shores, which give dis- 
tinctive climatic peculiarities to certain districts, notably 
to the Undercliff. These peculiarities are of no incon- 
siderable value in the treatment of those diseases which 
require a mild, equable temperature, a comparatively 
small rainfall, and protection from certain noxious winds. 
The Undercliff extends for nearly seven miles from 
Bonchurch to Blackgang, with an average breadth of a 
third of a mile, and is completely sheltered from the 
north-east, north, north-west, and west winds of the 
Uppercliffi—a range of lofty downs of chalk and sand- 
stone which rise boldly behind the successive terraces 
in elevations varying from 400 to 600 feet. Since the 
Undercliff terminates in an unbroken perpendicular sea- 
cliff from 60 to 80 feet in height along its whole extent, 
the situation is not close or confined, but open and airy, 
and affords, besides, certain material advantages in the 
mitigation of sea fogs and low night temperatures. The 
broad belt of the Solent and Spithead separating the Isle 
of Wight from the mainland, and the position of the 
Undercliff in the extreme south of the island, considered 
with reference to the prevailing winds of the Channel, are 
also important factors in the climate of the district. 
In more recent years several other meteorological sta- 
tions have been established in other parts of the island 
and on the adjacent coast of Hampshire, from the obser- 
vations of which a comparison may be made of the 
climatologies of this part of the South of England. 
On an average of the last twenty-one years the annual 
rainfall of Ventnor was 30°00 inches, being all but iden- 
tical with that of Osborne and Bournemouth. The 
amount rises successively at Hurst Castle, Ryde, and 
Newport, the rainfall at the last place being 34°20 inches, 
1 ““The Climate of the Un lercliff. Isle of Wight, as Deduced from Forty 
Years’ Consecutive Meteorological Observations,” by J. L. Whitehead, M.D. 
