420 
NAIURE 
| March 23,1871 

naked, the Mashonas are well clothed, and practise the art of 
smelting and working iron in great perfection. He exhibited a 
pecimen of gold, weighing 27 ounces, extracted by his men 
{rom the quartz reefs. Mr. Galton spoke of the great additions 
made by Mr. Baines, in this journey, to our topographical know- 
jedge of Africa; and Mr. Dunlop stated that quartz had now 
been found in the country yielding eight and ten ounces ef gold 
to the ton, and that the country was a suitable field for British 
enterprise. 
Linnean Society, March 16.—Mr. G. Bentham, president, 
in the chair. Col. Grant was elected a fellow.—Prof. Oliver 
exhibited specimens of Cufania cinerea, Poepp. belonging to 
the order Sapindaceze, from the Kew Herbarium, in which the 
seed, partially surrounded by an arillus, splits open, and the 
exalbuminous embryo falls out, leaving the testa and arillus on 
the tree, the only instance known of such dehiscence of the seed 
itself—An extract was read from a letter from General Munro 
to Dr. Hooker, describing the vegetation of a little known part 
of the island of St. Vincent, in the West Indies —Mr. Henry 
Reeks exhibited a series of forms of Asfidiam from Woodhay in 
Ifampshire, which he considered showed a regular gradation be- 
tween A. aculeatum and A. angulare of authors.—Notes on 
Capparis galeata and C. Murrayti, by Mr. N. A. Dalzell, who 
believes that these two perfectly distinct species have generally 
been confounded with one another.—Dr. B. Seemann exhibited a 
Jamellicorn beetle from Nicaragua, one of the largest Coleoptera 
yet found in America. 
Paris 
Academy of Sciences, March 13.—A sharp discussion 
arose on reading the frocés verbal of the last sitting. General 
Morin complained’ that it was stated by M. Sainte Claire Deville 
that science had not received proper application in war- 
fare. He was obliged to confess that the French artillery was 
not up to the times, since they had no steel guns. Steel guns had 
heen condemned as useless by the committee because His Majesty 
was a great artillerist.—The report of the death of M. Becquerel, 
sen., during the investment of Paris was stated to be in- 
correct. It wasreally M. Dumeril, the son of the celebrated elec- 
1rician, who had died ; M. Becquerel, sen., was not present at the 
sitting. —M. Leverrier was present at the sitting. M. Dumas 
yead for the learned astronomer a long memoir on the Defence 
of the Rhone Valley, to which M. Leverrier was attached during 
the investment of Paris. He resided at Nismes and not at Mar- 
seilles, as had been said. The principal feature of this work is the 
construction of an apparatus for optical signalling. This appara- 
tus can be used during day-time, and signals can be seen at a 
distance of eight miles by day with the naked eye.—M. Serret, 
J’resident of the Scientific Delegated Commission at Tours and 
then at Bordeaux, read over a reclamation on behalf of M. 
Louccarut, who claims a right to the invention of the instrument 
manufactured by M. Janssen for guiding aéronauts. M. Serret gave 
a certificate testifying that M. Bouccarut in the month of Septem- 
ber communicated an instrument similar to M. Janssen’s com- 
pass. If so why did the Delegated Scientific Commission keep 
the communication without warning the Government of National 
Defence at Paris, where the instrument was much wanted, as 
not less than ten balloons were lost, five of them in the sea, 
because aéronauts were unable to see their way? M. Delaunay read 
a declaration stating that he acknowledged that Mr. Hennessy 
had used the same arguments as himself against Mr. Hopkins’ 
theory relative to the fluidity of the interior parts of the earth. 
But the adhesion given by Sir W. Thomson and other learned 
men to Mr. Hopkins’ views is the reason why he did not regret 
having again raised this much controverted question.—M. de 
Fonvielle presented a paper explaining why the gas inside an 
aézostat very often suddenly increases in density. The phe- 
nomenon is common in warm weather when the gas is saturated 
with vapour from the water of the gasometer, and also when the 
balloon is rising at a quick rate. The increased density is owing to 
a quick refrigeration corresponding to the dilatation of the gas 
when the balloon is ascending toa higher level. It is an illustra- 
tion of the law of equivalence of force and heat. It is the 
same experiment as is noted in Tyndall’s special treatise on that 
subject, when damp air is placed under an air-pump worked 
at a certain rate. ‘The movements of the balloon being able to 
he controlled, it is possible, through an aéronautical ascent, to 
come to a numerical conclusion.—M. Bouley delivered an 
interesting lecture on the cattle plague, which is one of the most 
important topics of the moment, He gave conclusive evidence 

that it was imported by the Prussian armies. The plague has 
had really terrific effects in the provinces. Ona sea coast the 
carcasses of infected animals were so numerous that it was im- 
possible to bury them. The authorities were obliged to fill with 
the putrid cargo old hulks, which were sunk by cannon balls 
from a distance. He said that infected animals were not un- 
wholesome in their flesh. A secret committee was opened on the 
question, proposed by M., Sainte Claire Deville. 


DIARY 
THURSDAY, Marcu 23. 
Roya Society, at 8.30.—Experiments on the Successive Polarisation of 
Light, with the Description of a New Polarising Apparatus: Sir Charles 
Wheatstone, F.R.S.—On an Approximately Decennial Variation of the 
Temperature at the Observatory Cape of Good Hope, viewed in connection 
with the Variation of the Solar Spots: E. J. Stone, F.R S. . 
Society oF ANTIQUARIES, at 8.30.—On Flint Implements and other Antiqui- 
ties from Kent: J. Brent, F S.A.—On Miscellaneous Antiquities from 
Leicestershire : Rev. Assheton Pownall, F.S.A. 
Royat InstiTuTIon, at 3.—Davy's Discoveries: Dr, Odling. 
Lonpon InsTITUTION, at 7.30.—On the Colonial Question: Prof. J. E. 
Thorold Rogers, M.A. 
FRIDAY, Marcu 24. 
QuexketrT Microscopicat Cuuvp, at 8. 
Royat INsTITUTION, at 9.—Colour: Prof Clerk Maxwell. 
Royat CoLLeGE oF SURGEONS, at 4 —On the Teeth of Mammalia: Prof. 
Flower. 
SATURDAY, Marcu 25. 
Royat InsTITuTION, at 3.—Spirit of the Age: Mr. O'Neil. 
Roya Scuoot or MInEs, at 8.—Geology : Dr. Cobbold. 
MONDAY, Marcu 27. 
Roya GEOGRAPHICAL SOCIETY, at 8.30. : 
INSTITUTE OF ACTUARIES, at 7.—On the Equitable Appointment or a Fund 
between the Life-tenant and the Reversioner: Andrew Baden. 
(Educa- 
Lonpon InstTiTuTION, at 4.—-On Astronomy: R. A. Proctor. 
tional Course.) ; 
Roya CoLiecE oF SurGEONS, at 4.—On the Teeth of Mammalia: Prof. 
Flower. 
TUESDAY, Marcu 28. 
Royat InstiTuTION, at 3.—Nutrition of Animals: Dr. M, Foster. 
WEDNESDAY, Marcu 29. 
Society or Arts, at 8.—On Woman's Work, with Special Reference to 
Industrial Employments: Miss Emily Faithfull. i 
Roya CoLLeGE oF SURGEONS, at 4.—On the Teeth of Mammalia: Prof. 
Flower. 
THURSDAY, Marcu 30. 
Roya Society, at 8.30. 
Soctety or ANTIQUARIES, at 8.30. 
Royat InstiTuTION, at 3.—Davy’s Discoveries: Dr. Odling. 
Lonpon InsTITUTION, 7-30.—On Economic Botany : Prof. Bentley. 
CHEMICAL Society, at 8.—Anniversary Meeting. 

CONTENTS Pace 
BOTANICAL MOSEUMS 4°. 3") is 0s © = =, © 15 Use 
PopuLAR'‘ORNITHOLOGY.s 2° 2°. 30. 6s ‘oe cl ss) 
Our Book Saerr fe 3 el Se ee eee 
LETTERS TO THE EDITOR :— 
The Teaching/of Science... o>) eso. a) oe) ane ee 
Forms of Clouds —W. pE Fonvigtte (With Illustration.) . - 405 
The Limits of Numerical Discrimination, . . . . . « . . + 405 
Books Wanted.—H. J. WATSON . © 18 Sole) + Xn noe 
Quinary Music’) (6.5)! iss sss cf br ee ei 
The Earthquake.—Rev. S. J. Perry; C. E. pe Rance, F.G.S.; 
Dr. G. H. SAVAGE oo) eos) eo) tele” ep UNS aS 
Luvar Halos.—S, BARBER, 5... \s, .» ¢ sls a Vee 407 
Sciencein schools: a4 aot in cada) cue re eee eee es) 
Morell’s Geometry —J. R. MorELL . . . . . . . . . © « 407 
Work and Force.—Dr, J. Hopkinson ; Rey. H. HiGHToN. . . 407 
IAMERICAN, NOTES 4; 35 (6: 1c) km Je) “sp Spelt esta Ce 408 
Tue Science AND ART DEPARTMENT. . . . . 2. - « 2 « + 408 
AuGusTus DE Morcan. By ArtHuR C. RanyArD . .. . . . 409 
Papers on Iron anv Steet. IV. THE BessEMER Process (con- 
we By W. Marrigu Wixriams, F.C.S. (With Tilustra- 
hOTEs) 0) 4) win “a Ae eS ie Ge 8) co, el Bk 8) IRL "ey aires pe vem eee 
Science IN GOVERNMENT Worksuops. (With I/lustvations.). . . 410 
NOTES 2's) pl eye. 8) slye os sewn gisuan 5) gag Deen eee eae 
Rerort on Deep SeA RESEARCHES (CONTINUED). By Dr. W. B. 
CarPENTER, F.R.S., and J. Gwyn JEFFreys, F.R.S. (With Iilus- 
trations.) ° @. sey tor) or te Wak tp imme Toll = fo.” lo ce name 
Scumewrivic SERBES, .6<(e Sus ve GUE so Oe - 417 
SocieTIesiAND:AGADEMIES) . 5. as cid Rupee es (2 6 ene 418 
DIARY ade ss}@ eden rise Re ete Cea 
420 
: 
