April 13, 1882] 
SCIENTIFIC SERIALS 
THE most recent numbers of Trimen’s Fournal of Botany 
(224-232) run rather strongly on phanerogamic, descriptive 
and geographical botany. The diligence of English observers 
seldom fails toadd two or three species to the British flora every 
year, either by absolute discovery, or by the separation of well- 
marked varieties. Three of these are described and figured in 
the numbers before us, viz. Spartina Townsendi, Groves, 
Agrostis nigra, With., and Senecio spathulefolius, DC, There are 
various other descriptions of critical forms, and papers on the 
flora of English districts or of foreign countries ; also on British 
Characez, and on marine Alge new to Devon and Cornwall. 
Among the more interesting illustrations are two coloured plates 
of Cinchona Ledgeriana, a new species described by Dr. Trimen. 
—The number for April, 1882, contains an interesting paper by 
C. P. Hobkirk, on the development of Osmanda regalis from 
the protballium, and several contributions to the extended con- 
troversy on the principles of botanical nomenclature. 
THE Bulletin of the Torrey Botanical Club continues to be 
well supported by such writers as Mr. G. Farlow, W. Trelease, 
T. Meehan, H. W. Ravenel, D. C. Eaton, G. E. Davenport, 
C. E. Bessey, and others; and indicates the careful manner in 
which botanical science is cultivated cn the other side of the 
Atlantic. The papers have chiefly a local value, though there 
are several on morphological points of more genera! interest. 
Bulletin de la Société Impériale des Naturalistes de Moscou, 
No. 2, 1882.—Studies on the fauna of terrestrial and fluviatile 
molluscs of Moscow, by C. Milachevitch.—The Amphibiz and 
Reptiles -of Greece, by Dr. Jacques von Bedriaga.—List of 
phanerogams and vascular cryptogams observed in the Govern- 
ment of Tula, by B. J. Zinger (with 2 plates).—Materialia ad 
zoographiam Ponticam comparatam, by V. Czerniaysky (with a 
plate).—On the phanerogamous flora of the Government of 
Moscow, by A. A. Fischer von Waldheim.—On Devonian 
fossils at the Shelon River, by H. Traut-chold (with a plate 
showing the new species, Zemtaculites ghaber, Aulopora arbor- 
escens, Cheleles intricatus, and Stromatopora Porchovensis),.— 
Annual report of the Society, and minutes of proceedings. 
SOCIETIES AND ACADEMIES 
LonpDon 
Royal Society, March 30.—‘‘ Description of Portions of a 
Tusk of an Australian Proboscidian Mammal (No/elephas aus- 
tralis, Ow.).” Py Prof. Owen, C.B., F.R.S. 
The author premised a quotation from the work by Count 
Strzelecki, entitled ‘‘ Physical Description of New South Wales, 
and Van Diemen’s Land”; 8vo, 1845, p. 312; in which the 
Count states that he had bought of a ‘‘ native,” employed at 
Boree, the station of Capt. Ryan, New South Wales, a molar of 
a Mastodon, of which the vendor stated that ‘‘similar ones, and 
larger still, might be got further in the interior.” This tooth 
was submitted by the Count to Prof. Owen, and was by him 
provisionally named Mastodon Australis, In subsequent exten- 
sive correspondence leading to the acquisition of the fossils from 
a wide range of Australian localities, described in successive 
volumes of the Philosophical Transactions, stress had been laid 
on the possibility of additional and more decisive evidence of a 
true proboscidian mammal having left its remains in the forma- 
tions or caverns whence the marsupial fossils had been derived ; 
but, as more than thirty years elapsed without the acquisition of 
such evidence, the author could add nothing to Count Strzelecki’s 
original announcement, 
Early in the present year he received portions of a tusk dis- 
covered or obtained by the late Mr. F. N. Isaac, in a “‘ drift 
deposit” of a ravine in a district of Darling Downs, about sixty 
miles to the eastward of Moreton Bay, Queensland, Australia. 
Prof. Owen had previously received fossils from that gentleman, 
and the present, apparently Mr. Isaac’s latest acquisition, was 
kindly placed in the Professor’s hands by Mr. E, Thurston 
Holland, nephew of Mr. Isaac. 
In his paper the author points out the several characters of 
true ivory presented by the portions of tusk, including those 
displayed in microscopic sections. Drawings of these sections, 
as seen under requisite magnifying powers, and others of the 
tusk, of the natural size, accompany the de-criptions. 
The tusk is one from the upper jaw, including a portion of 
the base and pulp-cavity; and, on the supposition that it has 
come from a mature animal, it indicates an elephant or mastodon 
NATURE 
571 
of somewhat smaller size than the existing species of India and 
Africa, 
The wide distribution of elephantine quadrupeds in Africa, 
throughout an extensive latitudinal range in Asia and Europe, also 
in both North and South Americas, indicates that at the periods 
when forest-growths were undisturbed by mankind, the huge 
quadrupeds deriving sustenance from the leaves, fruit, and tender 
branches of trees were coextensive therewith, Australia seemed 
to offer an exception, but the subject of the present paper justifies 
the belief in the further extension of the hugest land mammals 
over the tree-bearing surfaces of the earth. 
Turther quest in the localities indicated by Count Strzelecki, 
and more definitely made known by Mr, Isaac’s discovery, may, 
it is hoped, be rewarded by the much-desired materials for 
extending our knowledge of the characters of JVo/elephas. 
Mathematical Society, April 6.—S. Roberts, F.R.S., 
president, in the chair.—Messrs. Buchheim, Muir, and C, Smith 
were admitted into the Society.—The following communications 
were made :—The Algebraic solution of the modular equation 
for the septic transformation, G. S. Ely.—Note on the condensa- 
tion of skew determinants which are partially zero-axial ; and on 
a symmetric determinant connected with Lagrange’s interpolation 
problem, T. Muir.—On the analogue to the addition-equation 
for Theta functions, Rey. M. M. U. Wilkinson.—On the general 
equation of the second degree referred to tetrahedral coordinates, 
Rey. A. J. C. Allen.—On certain loci and envelopes belonging 
to triangles of given form inscribed and circumscribed toa given 
triangle, Prof. Wolstenholme.—On binomial biordinals, Sir J. 
Cockle, F.R.S.—On the coordinates of a plane curve in space, 
H. W. Lloyd Tanner.—On Polygons circumscribed about a 
cuspidal cubic, R. A. Roberts. 
Physical Society, March 25.—Prof. Clifton, president, in 
the chair.—New Members. Mr. M. J. Jackson, B.A., Mr. 
Nazarus Fletcher, British Museum.—Mr. Shellford Bidwell read 
a paper on the electric resistance of a mixture of sulphur and 
carbon. These experiments were begun in December, 1880, to 
ascertain if the mixture in question was sensitive to light like 
selenium. Sulphur was melted and mixed with powdered 
plumbago (the best proportions being 20 parts by weight of the 
sulphur to 9 parts of the plumbago, The mixture was poured 
into moulds, and quickly cooled, yielding plates and sticks. 
When exposed to the light of a gas-flame, an increase in resist- 
ance was noticed, and was proved to be due to the heat of the 
flame, not the light, by experimenting with different sources of 
light and coloured screens of glass. As both carbon and sulphur 
decrease in resistance under heating, the opposite effect of the 
mixture is anomalous, and Mr, Bidwell explains it by supposing 
that the mixture is mechanical, and that heat expanding the size 
of the insulating sulphur crystals, separates the conducting 
carbon particles further apart, and increases the resistance of the 
mass. Cells of this compound were made like selenium cells by 
spreading it between the parallel turns of two fine platinum wires 
wound round a mica plate and the rise of resistance for temperature 
carefully measured. At 14° C. the resistance was 9100 ohms ; 
at 55° C. it was 5700 ohms, and the rise was in greater ratio 
than the rise of temperature. Mr. Bidwell also found that these 
cells would transmit speech when connected in the circuit of a 
battery and a Bell telephone. They also acted as a thermo- 
scope, when employed after the manner of a thermopile. 
Mixtures of shellac and graphite, of paraffin and graphite, 
&e., were also tried with like results. In reply to Prof. 
Macleod, Mr. Bidwell said the resistance of the cells decreased 
soon after being made. Mr. Bidwell also stated, that acting on 
a suggestion of Dr. Hopkinson, he had found that the resist- 
ance diminished under a more powerful current foree.—Mr. C. 
V. Boys read a paper on a new method of finding the index of 
refraction of lenses, based on the general principle employed 
by Foucault, of causins the ray of light to return on the same 
path. Prof. Clifton stated that a similar method was now em- 
ployed by him at Oxford, and was useful for small lenses. — 
Prof. Fitzgerald, of Dublin, showed mathematically that it 
was impossible for a small charge of static electricity, carried 
along by the earth, to move a magnet in its neighbourhood. 
Prof. Ayrton questioned this conclusion, and exhibited an appa- 
tus intended to test the point experimentally.—The meeting was 
then adjourned till April 22. 
Anthropological Institute, March 21.—Major-General Pitt- 
Rivers, F.R.S., president, in the chair.—The following new 
Members were announced :—Messrs. Francis Archer, William 
A. L. Fox Pitt, W. E. Maxwell.—Mr. Worthington G. Smith 
