Aug. 15, 1871] 



NA TURE 



317 



sun-spots and cyclones (enrth-spots), he woiikl find a close 

 harmony between them. Such a connection will probably be 

 found to exist over the globe generally ; but with reference to the 

 Indian Ocean it may be stated as a matter of fact, from Mr. 

 Meldrum's discussion of twenty-five years' observations, that in 

 the area lying between the equator and 25° south latitude, and 

 between 40° and 110° east longitude, the frequency of cyclones 

 has varied during that period directly as the amounts of sun- 

 spots. I am glad to be able announce that Mr. Meldrum, in 

 order to place the deductions on a still broader foundation, pro- 

 poses to investigate these laws on a plan perfectly in agreement 

 with our method of determining the areas of solar disturbances, 

 the results of whicli have been published from time to time during 

 the last ten years. Moreover the observations on the periodic 

 changes of Jupiter's appearance, and the obser\'ations of Mr. 

 Baxendell that the convection cuirents of our earth vary 

 according to the sunspot period — all these results, seemingly 

 solitary, but truly in mysterious harmony, point to the absolute 

 necessity for establishing constant photograpliic records 

 of solar and terrestrial phenomena all over the world. No 

 ^ astronomer or physicist should lose any opportunity of assisting 

 in this great aim, by which alone unbiassed truthful records of 

 phenomena can be preserved. What is more, no system of 

 observations can be carried on at a less expense. 



We have hopes of seeing the photographic method as applied 

 to sun-observations joined to the work of the Greenwich Obser- 

 vatory ; but what is furtlier wanted is the erection of instrumen*s 

 for photographic records and of spectroscopes in a number of 

 observatories throughout the world, so as to obtain daily records 

 of the sun and to observe magnetical and meteorological plieno- 

 mena continuously in connection with solar activity. Me;eoro- 

 logical observation is storing up useful facts ; but they can only 

 be dealt with effectually if investigated in close parallelism witli 

 other cosmical phenomena. Only when this is done may we 

 hope to penetrate tlie maze of local meteorological phenomena 

 and elevate meteorology to the rank of a science. The time has 

 really come not only for relieving private observers from the sys- 

 tematic observation of -solar phenomena, but for drawing close 

 ties between all scattered scientific observations, so as to let one 

 grand scheme embrace the whole ; and no method seems to be 

 so well adapted to bring about this great achievement than the 

 method of photographing the phenomena of nature, which in 

 its very principle carries with it all extinction of individual 

 bias. 



In conclusion I cannot refrain from making a passing allusion 

 to a Royal Commision, presided over by the Duke of Devon- 

 shire, which has been sitting for some time past ; for I believe 

 that its labours will have an important bearing on all that relates 

 to scientific education and the promotion of science in this 

 country. The time has come when the cultivation of science 

 must be protected and fostered by the State ; it can no longer be 

 safely left to individunl efforts. If England is to continue to 

 hold a high position among civilised nations, the most anxious 

 care must be given to the establishment by the State of such an 

 organised system for the advancement of science and the utili- 

 sation of the work of scientific men as will be in harmony with 

 similar organisations in neighbouring states — for examples, 

 France, Germany, and Russia. 



ArPENDI.X 



Certain conclusions at which Prof. Zollner arrives in the in- 

 vestigation of several points bearing on tlie theory which he 

 defends are, quite independent of the latter, of high scientific 

 value. 



First, with reference to the density of atmospheric air, which (in 

 accordance with the considerations mentioned in staling his views) 

 he supposes to fill the interstellar space everywhere, he assumes 

 for the purposes of calculation that the temperature of space is 

 that of melting ice, and finds that the lower limit of density for 



V- a portion of gas in space is — jg of that of the air at the earth's 



surface, a value so small that if amass of air which, at its ordinary 

 density upon the earth's surface, occupies a volume of one cubic 

 decimetre (a litre), were reduced to the density expressed by this 

 fraction, it would fill a sphere \vhose radius would not be tra\crsed 

 by a ray of light in less than 10^^ years. These values indicate a 

 density which would have no appreciable effect whatever upon 

 rays of light or upon the motion of bodies in space, and which 

 would become still less if the temperature of space be taken, with 

 Fourier, at — 6o''C., or with Pouillet, at — I32°C. But as every 

 solid body must, by virtue of its gravitative energy, condense the 



gas into an atmospheric envelope round itself, the density of the 

 latter will solely depend on the size and mass of the body. 

 Prof. Zollner finds by calculation that, for instance, the density 



of air thus forming an atmosphere round the moon must be "333 



of that of the air of the earth's surface. This is in accord with 

 the fact that no trace of a lunar atmosphere has as yet been de- 

 tected. Put the values become very great for the larger planets, 

 quite great enough to manifest absorptive effects upon tlie light 

 reflected from them. Considering that there are pecuHarities in 

 the spectra of Uranus, Neptune, and also of Jupiter, which 

 appear to indicate atmospheric influences, Prof. ZoUner's results 

 are not without deep interest, and certainly suggestive of further 

 inquiry. 



Secondly, with reference to the supposition that a body may 

 be at the same time under the influence of gravitative and elec- 

 trical agencies, it was necessary for the author of this theory to 

 discuse the quantitive difference in their effect upon ponderable 

 masses at a distance. The discussion shows that, if llie mass in- 

 creases, gravitation preponderates over electricity ; if the mass de- 

 creases sufficiently, the contrary takes place. It follows that the 

 cometary nuclei, as masses, are subject to gravitation, while the 

 attenuated vapours developed from them yield to the action of 

 free electricity of the sun. Prof Zollner has based upon Hankel's 

 numerous and careful researches on the determination of atmo- 

 spheric electricity, in absolute measure, an analytical inquiry into 

 the motion of a small sphere under the action of gravity and 

 atmospheric electricity, which leads to some remarkable results. 

 Supposing the free electricity of the sun to be not greater than 

 that repeatedly observed on the earth's surface, and to be uni- 

 formly distributed, it would communicate to a sphere having a 

 diameter of 11 millimetres and a weight of-fjijof a milligramme, 

 and starting from the sun, by the time it had moved as far away 

 as the mean distance of Mercury, a velocity per second of 

 3,027,000 metres, or 408 '4 German geographical miles.* This 

 velocity is such that in two days it would pass over a space of 

 70, 540,000 German geographical miles, a magnitude quite of the 

 same order as those recorded by cometary astronomy. The dis- 

 cussion was undertaken to prove that there is no need for 

 assuming tlie existence of any unknown repulsive agency, but 

 that electrical energy not greater than that observed on the 

 earth's surface is amply sufficient to account satisfactorily for the 

 phenomena presented by cometic trains. 



SECTION B 



CHEMICAL SCIENCE 



Opening Address by the President, Dr. J. Hall 

 Gladstone, F.R.S. 



One of my fellow-students in the laboratory of the late 

 Prof. Graham began the study of Chemistry because he wanted 

 to be a Geologist, and he had read in some Geological 

 Catechism that, in order to be versed in that science, it was 

 necessary, as a preliminary step, to gain a knowledge of Chemis- 

 try, Mineralogy, Zoology, Botany, and I know not what besides. 

 My friend became a chemist, and found tliat enough for the 

 exercise of his faculties. Vet the catechism had truth on its 

 side ; for so intertwined are the various branches of observa- 

 tional or experimental research, that a perfect understanding of 

 one can only be obtained through an acquaintance with the 

 whole cycle of knowledge. 



Yet, on the other hand, who can survey the whole field even 

 of modern Chemistry ? There was a time, doubtless, in the re- 

 collection of the more venerable of my auditors, when it was not 

 impossible to learn all that chemists had to teach ; but now that 

 our " Hand Book" has grown so large that it would take a 

 Briareus to carry it — and it requires a small army of abstractors 

 to give the Chemical Society the substance of what is done 

 abroad — we are compelled to become specialists in spi'.e of 

 ourselves. He who studies the general laws of Chemistry may 

 well turn in despair from the ever-growing myriads of trans- 

 formations among the compounds of carbon ; we have agricul- 

 tural, physiological, and technical chemists ; one man builds up 

 new substances, another new formula:; while some lo\e the 

 rarer metals, and others find their whole soul engrosied by the 

 phenyl compounds. 



How is this necessity of specialisation to be reconciled with 

 the necessity of general knowledge ? By our forming a home 

 * Fifteen to a degree of longitude on the Fquator. 



