M. Lemström proves by a great number of facts, supported by incontestable reasoning, that polar light is due to atmospheric electricity, of which he has proved the presence in the polar regions, often in the region of clouds, and sometimes even nearer the earth. He shows, as I have done, that this light is the consequence of electric discharges, which in these regions, constantly pervaded with humidity, operate in a slow, continuous manner, instead of instantaneously by shocks producing lightning, as takes place in equatorial regions and middle latitudes. He shows, with truth, that terrestrial magnetism, to which an exaggerated importance has been attributed, in the production of polar light, has only a very secondary part in this phenomenon. This part consists simply in giving to the luminous electric jets a certain direction they can follow because of their flexibility, which depends upon whether the medium through which they pass is gaseous. In support of his views in this respect, he refers to my experiments, by which I have demonstrated this influence, and the law by which, according to Plucker, it is governed. One very essential point upon which M. Lemström insists, and which has been noticed by several observers, particularly by Bravais, is that the crown formed in some cases by the rays of polar light is very far from having always for center the magnetic zenith; that is to say, the vertical line passing through the magnetic pole of the earth. In fact, although the formation of this crown depends upon the directing influence of the magnetism upon the electric currents which form the luminous jets, and is not, as M. Lemström very well proves, a simple effect of perspective, it must also depend upon the direction of the passage of the electric discharges through the atmosphere, a direction which itself changes with the conductibility more or less variable of the different atmospheric strata, so that the united effect of these two influences ought to give to the rays a curvature and a position which cannot always be the same. In short, the electric discharges which take place in the polar regions between the positive electricity of the atmosphere and the negative electricity of the terrestrial globe are the essential and only causes of the formation of polar light-light, whose existence is independent of that of terrestrial magnetism, which only imparts to it a certain direction, and in some cases a movement. These views I have always maintained in opposition to those who think they find in terrestrial magnetism, or rather, in the currents of induction which it can develop, the origin of polar light. I will not dwell upon various interesting circumstances, such as the presence of a dark segment at the base of the luminous arcs of the aurora borealis, in which M. Lemström sees, as I do, an analogous effect to the dark band produced at the negative électrode, in electric discharges through rarified air; or such as the influence of particles of ice suspended in the atmosphere, which I have also noticed. I will confine myself to one point which, I confess, had completely escaped me, and which is of great importance. Although, in my theory, the terrestrial currents which result from the electric discharges, the cause of polar light, ought to be directed from the north to the south, some are observed, either in the telegraph-wires or in their action upon the needle of the compass, which have a contrary direction, that is from the south to the north. The former, it is true, are much the more numerous and the more intense; but still the latter are apparent from time to time. M. Lemström attributes them to the currents of induction, and the elec tro-motive force which accompanies always the production of an electric spark, as M. Edlund discovered. He considers in fact, and with reason, the electric discharges which constitute polar light, as a series of an infinite number of sparks, and in this fact found a satisfactory explanation of the existence of currents in an opposite direction from that of the principal current, which is from north to south. The perusal of M. Lemström's article, while confirming me in the theoretical views I have advanced in regard to polar auroras, has shown me that there still remain many points to be explained of this interesting subject, especially in what concerns the propagation of electricity in air more or less damp, and reduced to a very low temperature and the influence of a very strong magnetism upon the electric discharges taking place under these conditions. I intend to pursue the subject with diligence. ON A DOMINANT LANGUAGE FOR SCIENCE. BY ALPHONSE DE CANDOlle, At the period of the Renaissance, Latin was the language employed by all the learned men of Europe. It had been carefully preserved by the Romish Church; and not one of the modern languages presented, at that time, a sufficiently rich literature to become its rival. But at a later period the Reformation disturbed the unity of the Romish influence. Italian, Spanish, French, and English gained successively regular idioms, and became rich in literary productions of every kind; and at last, eighty or one hundred years ago at most, the progress of science caused the inconvenience of the use of Latin to be felt. It was a dead language, and, in addition to that, was wanting in clearness, owing to its inversions, to its abbreviated words, and to the absence of articles. There existed at that time a general desire to describe the numerous discoveries that were being made, and to explain and discuss them without the necessity of seeking for words. The almost universal pressure of these causes was the reason for the adoption of modern languages in most sciences, natural history being the only exception. For this, Latin is still employed, but only in descriptions-a special and technical part, where the number of words is limited and the construction very regular. Speaking truly, what naturalists have preserved is the Latin of Linnæus, a language in which every word is precise in meaning, every sentence arranged logically, clearly, and in a way employed by no Roman author. Linnæus was not a linguist. He knew but little even of modern languages, and it is evident that he struggled against many difficulties when he wrote in Latin. With a very limited vocabulary and a turn of mind which revolted equally from the periods of Cicero and the reticence of Tacitus, he knew how to create a language precise in its terms, appropriate to the description of forms, and intelligible to students. He never made use of a term without first defining it. To renounce this special language of the learned Swede would be to render descriptions less clear and less accessible to the savants of all nations. If we attempt to translate into the Latin of Linnæus certain sentences in modern floras, written in English or German, we quickly perceive a want of clearness. In English, the word smooth applies equally to glaber and **The fifth chapter of the Histoire des sciences et des savants depuis deux siècles, 8vo, Genève, 1873. London, Dulan. Translated by Miss Miers, by permission of the author. Aun. & Mag. N. Hist., ser. 4, vol. xi. lævis.* In German, the construction of sentences indicating generic or other characters is sometimes so obscure that I have found it impossible, in certain cases, to have them put into Latin by a German, a good botanist, who was better acquainted than myself with both languages. It would be still worse if authors had not introduced many words purely Latin into their language. But, exclusive of paragraphs relative to characters, and wherever successive phenomena or theories are in question, the superiority of modern languages is unquestionable. It is on this account that, even in natural history, Latin is every day less employed. The loss, however, of the link formerly established between scientific men of all countries has made itself felt. From this has arisen a very chimerical proposal to form some artificial language which should be to all nations what writing is to the Chinese. It was to be based on ideas-not words. The problem has remained quite devoid of solution; and even were it possible, it would be so complicated an affair-so impracticable and inflexible-that it would quickly drop into disuse. The wants and the circumstances of each epoch have brought about a preference for one or other of the principal European languages as a means of communication between enlightened men of all countries. French rendered this service during two centuries. At present variens causes have modified the use of this language in other countries, and the habit has been almost everywhere introduced that each nation should employ its own tongue. We have, therefore, entered upon a period of confusion. What is thought to be new in one country is not so to those who read books in other languages. It is vain to study living languages more and more; you are always behindhand in the complete knowledge of what is being published in other countries. Few persons are acquainted with more than two languages; and if we try to pass beyond a certain limit in this respect, we rob ourselves of time for other things; for there is a point at which the study of the means of knowledge hinders our learning. Polyglot discussions and conversations do not answer the intentions of those who attempt them. I a:n persuaded that the inconvenience of such a state of things will be more and more felt. I also believe, judging by the example of Greek as used by the Romans and French in modern times, that the need of a prevailing language is almost always recognized; it is returned to from necessity after each period of anarchy. To understand this we must consider the causes which make a language preferable, and those which spread its employment in spite of any defects it may possess. Thus, in the seventeenth and eighteenth centuries, motives existed for the employment of French in preference to Latin throughout Europe. It was a language spoken by the greater part of the educated men of The word glaber, in botany, means bald or not hairy, which is applied to other parts as well as the head; and lavis, smooth, not rough; but I know they have both been carelessly translated "smooth," as M. de Candolle implies.-J. E. G. the period-a language tolerably simple and very clear. It had an advantage in its resemblance to Latin, which was then widely known. An Englishman, a German, was already half acquainted with French through his knowledge of Latin; a Spaniard, an Italian, was three parts advanced in his study of the language. If a discussion were sustained in French, if books were written or translations made in this language, all the world understood. In the present century, civilization has much extended north of France, and population has increased there more than to the south. The use of the English tongue has been doubled by its extension into America. The sciences are more and more cultivated in Germany, in England, in the Scandinavian countries, and Russia. The scientific center of gravity has advanced from the south toward the north. Under the influence of these new conditions, a language can only become predominant by presenting two characters: first, it must possess sufficient German and Latin words or forms to be within reach at once of the Germans and of the people who make use of Latin tongues; secondly, it must be spoken by a considerable majority of civilized people. In addition to these two essential conditions, it would be well for the definitive success of a language that it should also possess the qualities of grammatical simplicity, of conciseness, and clearness. English is the only language which may, in fifty or a hundred years offer all these conditions united. The language is half German and half Latin. It possesses German, words, German forms, and also French words, and a French method of constructing sentences. It is a transition between the principal languages used at present in science, as French was formerly between Latin and several of the modern languages. The future extension of the Anglo-American tongue is evident. It will be rendered inevitable by the movement of the populations in the two hemispheres. Here is the proof, which it is easy to give in a few words and a few figures. At the present time the population stands thus, (Almanach de Gotha, 1871:*) English-speaking peoples in England, 31,000,000; in the United States, 40,000,000; in Canada, &c., 4,000,000; in Australia and New Zealand, 2,000,000; total, 77,000,000. German-speaking peoples in Germany and a portion of Austria, 60,000,000; in Switzerland, (German cantons,) 2,000,000; total, 62,000,000. French-speaking peoples in France, 36,500,000; in Belgium, (French portion,) 2,500,000; in Switzerland, (French cantons,) 500,000; in Algeria and the colonies, 1,000,000; total 40,500,000. Now, judging by the increase that has taken place in the present cen tury, we may estimate the probable growth of population as follows: † *No notice is here taken of the English-speaking people in India and the East.-J. E. G. t Almanach de Gotha, 1870, p. 1039. |