WE have already had something to say about the spots on the sun, and their curious relations to terrestrial phenomena. We have seen that the occurrence of the aurora-borealis and the cyclical disturbances of the compass-needle are determined by those gigantic solar storms which give to the disk of our great luminary its spotted appearance. We have also given some of the facts which seem to indicate a remarkable coincidence between the periodicity of the spots and the periodicity of Asiatic cholera, though we freely admit that this coincidence may be purely fortuitous. To distinguish between those cases of agreement, among different orders of phenomena which are evidence of true causal relationship, and those which are merely accidental, is often possible only at an advanced stage of inquiry, and after a very wide induction of instances, or a complicated deduction from known principles. The scientific student is, however, quite legitimately employed in hunting up instances of coincidence, even though he must be content to let them stand as empirical facts for want of adequate data for interpreting them. In this humble way, astronomy, the most advanced of the physical sciences, began its career by the ascertainment of sundry periodicities in the heavens for which no one could assign the reason ; and now it is just this initial sort of work which chiefly concerns us when we study meteorology. In a recent interesting article in Nature, Mr. J. N. Lockyer observes : “ Surely in meteorology, as in astronomy, the thing to hunt down is a cycle, and if that is not to be found in the temperate zone, then go to the frigid zones or the torrid zone to look for it, and if found, then, above all things, and in whatever manner, lay hold of it, study it, record it, and see what it means.”
Now, it is remarkable that the first decided periodicity which has been observed in storms of rain and wind carries us directly to the sun-spots. Naturally, the place for seeking to detect such periodicity should be within the tropics, where the winds blow so much more uniformly than in the temperate zones. A year ago, when Mr. Lockyer went to India to observe the eclipse of the sun, he found that a regular period of about eleven years in the maximum intensity of the monsoons was generally recognized in Ceylon. Every eleventh year, as a general rule, there occurs the greatest violence of the wind and the greatest quantity of rainfall. Sometimes, as might be expected, the cycle is not entirely regular, and twelve or thirteen years elapse before the recurrence of maximum intensity. But, on the whole, the undecennial period seems to be quite strongly marked ; while toward the middle of it occurs the minimum of wind and rain. Again, these eleven-year cycles are said to combine by threes to form grand cycles of thirty-three years, which curiously correspond with the epochs at which cholera breaks out with greatest virulence in India.
Confirmatory evidence of the highest value is supplied by the observations of Mr. Meldrum. After showing that the cyclones, both in the Caribbean Sea and in the Indian Ocean, vary in number according to the frequency of sun-spots, this careful observer has proceeded to study the rainfall of Queensland, Adelaide, and the Mauritius, with the view of ascertaining its periodicity. As the cyclones are usually accompanied by prodigious rains, the periods of excessive rain might be expected to agree with those of extreme atmospheric disturbance, so that the evidence obtained from the former ought to confirm the testimony of the latter. This expectation is quite borne out by the facts. At the three points selected for observation, the total rainfall of the three years 1859 - 1861, during the maximum of sun-spots, exceeded by fifty inches the total rainfall of the three years 1866-1868, during the minimum of sun-spots. In Australia, twentytwo years of observations give a difference of eighteen inches between the rain of a year that is rich and that of a year that is poor in sun-spots, Mr. Lockyer finds a similar difference of thirty inches at the Cape of Good Hope, and of fifty inches at Madras. And from all this he rightly concludes that, in and near the tropics at all events, the effect of the solar storms upon terrestrial atmospheric disturbance is demonstrated. For although the desirable accumulation of proofs will necessarily require that systematic observations should be kept up for many years, nevertheless, the facts thus far obtained point all in one way. At six or eight different points, and whether we interrogate the winds or the rains, the verdict is unanimous. When the atmosphere of the sun is violently agitated, the tremor communicates itself to the atmosphere of our planet. Deductively, too, this is no more than what we might have expected. To minds unfamiliar with science, there may, indeed, seem to be no very obvious connection between a tornado on the sun, ninety million miles off, and a drenching rain on the Indian Ocean. The production of a storm on the earth, however, is only a question of heat, or of electricity, or, more properly speaking, of heat and electricity. A sensible variation in the quantity of heat daily received from the sun must give rise to atmospheric currents, and bring about a condensation of aqueous vapor. And there can he no doubt that the blackening of several hundred thousand square miles of the sun’s fiery envelope must perceptibly alter the amount of heat which he radiates upon the earth. The magnetic disturbance, also, shown in the aurora-borealis, and in the swaying of the Compass-needle, cannot well be without its effect upon the electric equilibrium of the atmosphere. Thus, in both ways, the production of storms is brought about.
As already observed, the correspondence between these sets of phenomena is most readily detected in tropical countries, where the winds ordinarily blow with great uniformity, and where rains fall at comparatively regular intervals. With the wider variations of temperature in the temperate zones, the phenomena of wind and rain become much more complicated and irregular in appearance. Even supposing the legitimate effects of the sun-spot to be the same over all parts of the earth, we must expect, in many localities, to find those effects obscured by other circumstances. In New England, the years 1870, 1871 were unusually dry years, though the number of sun-spots was at the maximum, and the auroral displays were frequent and brilliant. Mr. G. J. Symons, in tabulating the results of observations on the British rainfall from 1725 to 1869, finds few signs of an elevenyear period, though the extreme variations during these one hundred and forty-four years are so far apart as fifty-eight and one hundred and thirty-eight inches. In Canada, there was less rain in 1859 - 1861 than in 1853 - 1857, though the former were maximum years for sun-spots. Observations at New Bedford, in Massachusetts, during the years 1832-1849, give clear indications of an eleven-year period, but with the circumstances just reversed. During the years of frequent sun-spots, the rainfall is fifteen inches less than during the opposite years. A similar result is strongly brought out in Palestine and France, and somewhat less decisively in Italy ; while from the data furnished by Switzerland, it is difficult to draw any conclusion.
The notable feature of these statistics is, not only that the law so clearly traceable in the tropics is, to a great extent, masked in the north temperate zone, but that over a considerable portion of the latter area its workings seem to be diametrically reversed. The periodicity is, to some extent, traceable ; but here the frequency of sun-spots seems to be accompanied by dryness, rather than by wet weather. A new consideration, however, ought to be taken into the account. Mr. Symons, in reviewing the papers of Mr. Lockyer and Mr. Meldrum, observes that it is worth while to consider “ whether the total precipitation over the surface of the globe can be expected to be increased by increased cyclonic energy. Increased rainfall surely means increased extraction of moisture from the air, and that involves one of two facts : (1.) increased evaporation to supply the increased demand ; or, (2.) rapid and great desiccation of the atmosphere. Without expressing a dogmatic or fixed opinion, it certainly seems to me more likely that the effect of cyclones is simply to alter the locality of deposition,” rather than to increase its aggregate amount. Or, in other words, the very disturbance set up in the tropics by the altered solar radiation may, by the tremendous rains thus occasioned, so far drain of its moisture the general atmosphere of the globe as to bring about a season of comparative drought in the temperate zones.
In view of this very reasonable qualification, Mr. Symons is no doubt,justified in saying that he should by no means regard the connection between rainfall and sunspots as disproved by a set of statistics exactly opposite to those obtained by Mr. Meldrum in the Indian Ocean. It would seem probable that over a considerable part of the earth’s surface such statistics must be forthcoming. And the whole question serves to illustrate the truth, so often exemplified, that mere statistics can enlighten us but little when given without the needful deductive interpretation.
If it should turn out, on further inquiry, that the observed coincidence between the periodicities of the sun-spots and of Asiatic cholera—as noticed in our gossip of last August — answers to any real causal connection between the two sets of phenomena, the explanation will probably have to be sought in the climatic effects traceable to the sun-spots. We shall simply have to speculate on the probable pathological consequences of an excessively wet or an excessively dry season, in Hindustan. Meanwhile we may be content with noting the curious parallelism.
To change the subject, —the little country of Holland, which has done so much for the political and religious emancipation of mankind, and which has always produced its full quota of literary and scientific workers, is now becoming distinguished for its achievements in the department of psychology. Dr. Van der Wijck has lately begun to sum up his extensive and profound studies in the first volume of his Zielkunde, which will form, when completed, a remarkably thorough treatise on psychical phenomena. This work covers very much the same ground as that which is covered by Professor Bain’s treatises on The Senses and the Intellect, and The Emotions and the Will; but Dr. Van der Wijck, while basing his work, equally with Professor Bain, upon the latest results of physiological inquiry into the relations between physical and psychical phenomena, nevertheless occupies an entirely independent ground with reference to the materialistic implications which are too generally Supposed to be inseparable from these conclusions. The close student of recent philosophical inquiry will regard it as significant, that Dr. Van der Wijck concludes an elaborate scientific inquiry into the mode and conditions of mental action with the declaration that idealism is the only hypothesis concerning the relations of matter and mind which is both consistently deduced from the data of consciousness and verified by them. The learned author very sensibly argues that the existence of consciousness we know directly and immediately, while the existence of matter, save as a mode of affection of consciousness, is merely the result of a complicated series of inferences. We have not space to argue or illustrate this point; but it is worth noting by those who think that a writer who talks about nervecentres in connection with consciousness must needs be a materialist.
Max Müller has been delivering a lecture at Liverpool concerning Darwinism as tested by the phenomena of language. We cannot give a full abstract of his argument, which will most likely be published before long, but there are one or two points which may profitably occupy our attention for five minutes. There is a fallacy, says Max Müller, latent in the very word “development,” for it rubs out the differences among things, — not only the difference between ape and man, but the difference between black and white, or between high and low, or between hot and cold. Very well ; if Max Muller will find for us an absolute distinction between high and low, or between hot and cold, we will do our best to herald him as a greater discoverer than Newton and a subtler thinker than Spinoza. What the word “ development ” — or rather the word “ evolution ” — implies, is that nothing is itself without being at the same time more or less of something else; and of all the truths yet discovered in science or philosophy, this is unquestionably the deepest.
One further assertion of Max Müller’s deserves serious notice. When Mr. Darwin says that some savage languages have no abstract terms, Max Müller replies that such common words as father and mother are abstract terms (!). Now this is because Müller is pre-eminently a Sanskritist, or Aryan scholar of the old school. Accordingly he holds that pa-tar and ma-tar are formed from Old Aryan roots pa and ma, with the suffix tar, denoting the agent, and that the root pa means “ to protect,” etc.; all of which, if it be really sound philology, would show only that the. Old Aryan language was spoken by a race which had already acquired considerable capacity for abstraction and generalization. But the Old Aryan language is only a few thousand years old, and no such language was talked by primitive men, who probably dealt but sparingly with time-hallowed “roots,” and signified their states of consciousness by grunts which, if quotable, would go but little way toward showing their capacity for abstract reasoning. But upon this we need not enlarge. We say only this, that to cite IndoEuropean examples in discussing primeval language is about as pertinent as to cite the laws of Manu in discussing primeval society. It is equivalent to forgetting all about the kitchen-middings, and it ignores contemporary savages into the bargain.