476 



NATURE 



[March 20, 1879 



motion performs work. Conversely Mr. Crookes finds that the 

 stream of molecules from a - pole in vacuo is electrified, and 

 may be deflected by a magnet. It is upon that fact that Pro- 

 fessors Ayrton and Perry have based then- theory, which is easily 

 explained by supposing the earth to be an isolated sphere with a 

 static charge residing on its surface. Then, since each electrified 

 particle at the surface will be moving relatively to a point in the 

 interior, it follows that the interior must be magnetic. The 

 theory is independent of the substance of the interior ; but in 

 order to simplify the working the authors treated the case of a 

 solid iron ball, and curiously enough arrived at the result 

 expressed by Biot's law for the distribution of magnetism on the 

 surface of the earth — 



12 = M Vi + 3 cos=* e, 

 and similarly they found that if the earth were electrified to the 

 potential of lo* volts, relatively to interplanetary space, its mag- 

 netisation would be as it is. If the earth were alone in the uni- 

 verse, then, by this theory, it would have its own magnetic state 

 by virtue of its electric charge and axial rotation. If other 

 bodies in the universe, however, had their magnetic states too, 

 these would influence the earth's, and hence we should have 

 terrestrial tides and storms of magnetic force, such as are known 

 to exist, as, for instance, when changes take place in the sun's 

 atmosphere by .approach of planets or other causes. Lastly, 

 the iron in the interior of the earth may give it a certain amount 

 of coercitive force, but the theory does not rest on this. — Dr. J. 

 Hopkinson then read an account of some experiments made with 

 the quadrant electrometer, which showed that Clerk Maxwell's 

 formula for the sensibility of the electrometer — 



where A and B are the potentials of the two pairs of quadrants, 

 and C the potential of the needle, only holds good when C (the 

 charge of the jar or needle) is less than 200 Daniell elements. 

 Above that a different law appears to hold. Dr. Hopkinson 

 also remarked that any degree of low sensibility down to zero 

 could be got from the electrometer by connecting a condenser to 

 each pair of quadrants and adjusting their capacities. — Mr. F. 

 D. Brown described his apparatus for maintaining constant tem- 

 peratures and pressures. A constant temperature can be ob- 

 tained if the pressure can be kept constant. The vessel in which 

 the constant pressure is desired communicates with an air-pump 

 by, a pipe in which a movable tap or valve is placed. By opening 

 or, closing this tap the pressure is regulated. This is effected by 

 an electric clutch arrangement. A mercury anemometer sends a 

 positive or negative current from a battery through the clutch 

 according as the pressure is too high or low, and this current 

 actuates the clutch to close or open the valve. The clutch con- 

 sists of an axle driven by a turbine to get power to work tho 

 valve, and the current, by means of electromagnetism, connects 

 the tap to the axle, which then opens or closes it as the case 

 may be. In this way a pressure varying' no more than one-fifth 

 millimetre each way can be obtained. - 



Linnean Society, March 6. — William Carruthers, F.R.S,, 

 vice-president, in the chair. — Mr. Thos. Christie exhibited and 

 made remarks on a series of specimens illustrating the little- 

 known and remarkable Australian Pituri plant ; also the os sepia 

 of a rare Australian cuttle-fish, obtained by Dr. Bancroft. — Mr. 

 R. Irwin Lynch showed a grovring example from Kew and dried 

 leaves of Xanthosoma appendiculatum, bearing pouch-like ex- 

 crescences from the midrib of the leaves. — The Vice-President 

 announced from the chair an alteration in the Bye-laws, Chap. 

 XIIL, proposed by the Council. — A letter was read from a cor- 

 respondent referring to the increased production of beet-root 

 sugar by careful artificial selection of the beet. The saccharine 

 produce of sugar-cane, on the contrary, remains stationary, if not 

 retrograde, and its continual multiplication from stolons some 

 regard as giving rise to various diseases. Crossing and selection 

 are now suggested as worthy of a trial in the interest of com- 

 mercial results. — A short paper on Entozoic Floridese growing 

 within living Bryozoa and Sponges, by Dr. P. F. Reinsch, was 

 read, and Mr. A. W. Waters exhibited in connection therewith, 

 under the microscope, specimens of Polyzoa containing parasitic 

 algse. — In a note on the fruiting of Wistaria sinensis in Evu-ope, 

 by Mr. W. T. Thiseltdn Dyer, the author avers from his own 

 and others' observations that plants trained on a garden wall at 

 Glyon, east end of the Lake of Geneva, yield abundance of 

 brown tomentose pods annually. Near the town of Geneva, 

 however, fruiting is of rarer occurrence, but again more frequent 

 at Lyons and the Rhone valley. Fruiting, he suggests, may be 



a question of temperature and not of nutrition, dependent on 

 presence or absence of support to the stem and branches. From 

 the above and other data, Mr. Dyer fails to see the evidence 

 of the antagonism of the vegetative and reproductive forces, 

 as asserted to be the governing law, according to Mr. Thos. 

 Meehan's experiments, and lately quoted by the Rev. G. Henslow. 

 If such barrenness were the case with its scandent habit, then 

 Wistaria sinensis would probably already be extinct. — The 

 Secretary read a paper by Mr. Edward J, Miers, on the classifi- 

 cation of the Maioid Crustacea or Oxyrhyncha. The Maioid 

 crabs have been placed by nearly all carcinologists at the head 

 of the Brachym-a, from the high degree evinced in their sensory 

 organs and nervous system, and the group, moreover, is interest- 

 ing on account of the variety of types. Though closely related 

 to the Oxystomata, the Oxyrhyncha differ from them in their 

 triangular buccal cavity and position of afferent branchial chan- 

 nel ; but Mesorhoea approximates on the part of the Partheno- 

 pidffi to the Oxystomatous type. From the Cancroid crabs 

 (Cyclometopa) typical Maiidse are distinguished by longitudinal 

 antennules and position of basal antennule joint, the Partheno- 

 pidse occupying an intermediate place between the rest of the 

 Oxjrrhyncha and certain Cancroid ea. The author reviews the 

 various classifications, and then gives a new synoptical arrange- 

 ment founded on certain anatomical configurations, &c., of their 

 buccal cavity, situation of afferent and efferent canals, antennules, 

 genital appendages, &c. He divides the group into 4 families, 

 12 sub-families, 106 genera, and 14 sub-genera, giving short 

 diagnoses of each. — Prof. J. Reay Greene, Dr. P. H. Stokoe, 

 Mr. R. Johnston (of Tasmania), Mr. B. S. Williams, and 

 Prof. J. Wood Mason, were balloted for and elected Fellows of 

 the Society. « 



Entomological Society, March 5. — ^J. W. Dunning, vicfr; I 

 president, in the chair. — The chairman referred to the great loss^ 

 sustained by the Society in the death of Mr. F. Smith, of the 

 British Museum. — Mr. C. Brogniart, of Paris, was elected a 

 Foreign Member and Mr. J. T. Harris, of Burton on-Trent, a 

 Subscriber to the Society. — Sir Sydney Saunders exhibited a 

 series of bees belonging to the genus Halticus, from Greece, 

 containing several remarkable new forms. The following papers j 

 were communicated : — On some new species of British hymenop- 

 tera, by Mr. Peter Cameron, and descriptions of some new 

 species of coleoptera from New Zealand, by Dr. Sharp. 



■'■''..,; CONTENTS Pagb 



Royal Agricultural College, Cirencester ,^^ •,, 453- 



Prof. Huxley's Hume. By Prof. J. Veitck . . . ''. Tr"'.'"'', '''. 453' 



Sachs's Venezuela ... .S3ia(. \,: 436- 



Our Book Shelf :— io».«>«»iluc*s -txi "iui Xi) - 



Bain's "Education as a Science" . , . , •• ..". '. ./ ., ' .-"^57 



Davis's " Life in Aiatic Turkey " . . ./ .' , '. ;- .., . •. '. . 457. 

 Letters to the Editor :— 



Tempel's Comet. — Dr. W. Valentiner 457 



Experiment with a Vacuum Tube. — H. Alfred Cunnington; 



William Crookes, F.R.S . . ; . . . 'f^ 



Tides in the Bay of Fundy.— Prof. J. D. Everett, F.R.S. . . • > v4jj8 

 End-on Gas-Vacuum Tubes in Spectroscopy. — Prof. PlAzzi 



S.myth 458 



Intellect in Brutes. — E, H. Pringle; Dr. John Rae; G. M. ; 

 Maurice Bhlsham ; W. P. Buchan ; Dr. Henry Muirhead ; 



R. Morton MiDDLKTON (With Diagraiii) 458 



Distribution of the Black Rat. — R. Morton Middleton . . . 460 g 



The United States Fisheries. — Chas. L. Jackson 460 



Plovers in the Sandwich Islands. — Capt. S. Long, R.N 460 



Unscientific Art. — ^John W. Buck 460 



On THE Possibility of Explaining the Continuance of Like in , 

 THE Universe Consistent with the Tendency to Tempera- 

 ture-Equilibrium. By S. ToLVER Preston 460 



Fritz Muller on a Frog havikg Eggs on its Back— On the ; 

 Abortion of the Hairs on the Legs of Certain Caddis-Flies, 

 &c. By Charles Darwin F.R.S., and Fritz Muller (IVifA 



Illustrations) , • • 462 



A Study in Locomotion, II. By Prof. Marey {Witk Illustrations) 46* 



Geology of Natal and ZuLULAND. By Chas. E. De Range . . 467^ 

 Our Astronomical Column :— 



Priies of the Paris Academy . 488 



Faye's Comet 469 



Biological Notes : — 



Fossils of the Amazonian Devonian . ., • • aVf >A * £• • • *^5 

 Australian Fossil Corals ..... . . .^r''\ ^W '.^. . .469 



Herring Culture . . 4^9 



Madagascar Forms in Africa 47° 



The '^Digger" Mollusc and its ParasiteSA'.VA.'?)'^ 47° 



Action of the Heart of the Crajrfish 47° 



Geographical Notes . . . . . . . . ,•.'.■■ i ^i • • ■ < 47° 



Edison's Telephone ............ .i.^v •• • 47i' 



Notes ', . . , 472 



The Paris Academy Prizes 475 



UNrVERSlTY AND EdUCATION.VI. INTELLIGENCE 475 



Ssientific Serials 475 



Societies and Acasbmibs 475 



