Popular Science Monthly/Volume 11/September 1877/Editor's Table
SPECTROSCOPIC DISCOVERY OF OXYGEN IN THE SUN.
CELESTIAL chemistry has taken another stride forward. In a paper recently read before the American Philosophical Society, and printed in the American Journal of Science and Arts, Dr. Henry Draper announces the discovery of oxygen gas in the sun, the fact being arrived at and verified by a long course of spectroscopic observations.
Viewed in any of its numerous aspects, this discovery is of immense interest. Whether as an extension of our knowledge of solar physics, solar chemistry, and the nature of the spectrum itself, or as throwing further light upon the constitution of the universe; whether as bearing upon cosmical theories that have attracted much attention, or as a triumph over the difficulties of complicated experiment, or, finally, as an illustration of hereditary genius in science, where a line of research opened brilliantly by the father nearly half a century ago, has been pursued with equal brilliancy to this crowning result—however regarded, this exploit of the younger Draper must command unqualified admiration.
As has been repeatedly shown in our pages, the elder Draper was one of the early and most successful explorers of the chemical relations of the luminous spectrum. He was a pioneer in this line of investigation, and the first to make extensive use of photography in this branch of research; and he was so far in advance of his time, that his discoveries were totally unappreciated. But he furnished the fortunate men who followed him with their tools to reap the splendid harvest of spectroscopic discovery, which has so impressed the world during the last eighteen years. We have never had any doubt that history would set all these things right, but the venerable doctor will at any rate be easy in the assurance that the sceptre has not departed from his family.
When it was established that the light emitted by vaporized and incandescent bodies gives spectra by which they may be identified, the passage was rapid to the discovery of chemical substances by the analysis of light. A study of the spectra of the sun and stars soon gave evidence that they contained forms of matter with which we are familiar upon earth. All the metals, for example, in a state of luminous vapor, yielded bright lines in the spectrum so distinctive in each case that there was no possibility of mistaking them. When these were carefully mapped and compared with the spectra from the sun and stars, such a startling mass of coincidences was at once disclosed, that there was no escape from the conclusion of a common causality, or that these metals exist also in the stellar bodies. There was but one serious difficulty. The lines obtained by the combustion of the metals were bright and colored, while the corresponding lines in the solar and stellar spectra were all dark. Kirchhoff resolved the difficulty in 1859, by showing how the bright lines may become dark lines by absorption in such conditions as the celestial bodies furnish; and it was thus not only established as a fact that there are various terrestrial metals in the sun and stars, but their mode of manifestation was brought into complete harmony with theoretical requirements.
The nebular hypothesis, which had been growing for a century, and which assumed the origin of all the bodies in the solar system from a common nebulous source, was, of course, at once and profoundly affected by the new revelations. It was proved that there are common elements extensively distributed among celestial bodies, which confirms the hypothesis that they have a common origin. Not only was there new and positive proof of the existence of nebulous matter in the celestial spaces, but the ultimate elements of which material Nature is constituted were shown to be universal, and the nebular hypothesis was thus strongly confirmed. Yet a difficulty at once arose, that the main predominant elements of terrestrial Nature were not found to exist in the sun and stars. The evidence, of course, was negative, but it was held by many to be weighty, in disproof of the nebular doctrine. If the non-metallic elements, it was said, which form the principal part of terrestrial objects, do not exist in the sun, the derivation of that body and of its encircling planets from the same primeval source is impossible. Dr. Draper has now proved that oxygen in large proportions exists in the sun (and probably nitrogen also); and his discovery can therefore only be regarded as lending further and more powerful confirmation to the nebular hypothesis.
Dr. Draper's paper, in the American Journal of Science and Arts, is accompanied by an illustrative diagram, which brings the demonstration before the eye of every reader. It exhibits the spectrum of the sun, and that which is produced from air, so juxtaposed that the fact and the extent of the identity of the lines in the two representations are seen at a glance. The matching and identification are even more complete than they were in the original experiments of Kirchhoff with the metals, for here it is not necessary to invoke a theory for the unification of bright and dark lines; the bright lines of the spectrum of oxygen being continuous with the bright lines of the solar spectrum. It is, indeed, because the solar oxygen reveals itself by bright lines that these have not been earlier detected, as they have been masked and concealed among the unoccupied luminous spaces, between the dark lines that have hitherto been the main objects of attention.
Dr. Draper has been occupied for several years with this investigation—in fact, he has grown into it. Besides Lis inherited attitude, and life-long training in this delicate line of manipulation, and his thorough familiarity with the peculiar difficulties of these investigations, his work could only have become successful by means of a combination of appliances, some of which are only lately available. His task was to produce a gas spectrum, and maintain it at a brilliancy which would admit of its being photographed alongside of that of the sun itself. Oxygen is made incandescent by electricity. The most ample, steady, and sustained command of this agent was therefore indispensable. This was secured by the Gramme machine, a dynamo-electric engine connected with a large induction-coil and a battery of Leyden-jars. The impulse was furnished by a Brayton's petroleum-motor, which "can be started with a match, comes to its regular speed in less than a minute, and preserves its rate entirely unchanged for hours together." This was belted to the Gramme machine, which, at its usual rate of running, gave 1,000 ten inch sparks per minute. This "torrent of intense electric fire," consisting of twenty ten-inch sparks per second, was passed through Plücker's tubes, containing oxygen, the spectrum of which is thrown upon a sensitive photographic surface, while the solar spectrum is formed beside it, and both are fixed together upon the tablet. The embarrassments of the investigation are thus referred to in Dr. Draper's paper:
"This research has proved to be more tedious and difficult than would be supposed, because so many conditions must conspire to produce a good photograph. There must be a uniform, prime-moving engine of two horse power, a dynamo-electric machine thoroughly adjusted, a large Ruhmkorff coil with its Foucault break in the best order, a battery of Leyden-jars carefully proportioned to the Plücker's tube in use, a heliostat which of course involves clear sunshine, an optical train of slit, prisms, lenses, and camera well focused, and, in addition to all this, a photographic laboratory in such complete condition that wet, sensitive plates can be prepared which will bear an exposure of fifteen minutes and a prolonged development. It has been difficult to keep the Plücker's tubes in order; often before the first exposure of a tube was over, the tube was ruined by the strong Leyden sparks. Moreover, to procure tubes of known contents is troublesome. For example, my hydrogen-tubes gave a spectrum photograph of fifteen lines, of which only three belonged to hydrogen. In order to be sure that none of these were new hydrogen-lines, it was necessary to try tubes of various makers, to prepare pure hydrogen and employ that, to examine the spectrum of water, and finally to resort to comparison with the sun."
In regard to the significance of the inquiry in relation to spectroscopic study, Dr. Draper remarks:
"We must, therefore, change our theory of the solar spectrum, and no longer regard it merely as a continuous spectrum with certain rays absorbed by a layer of ignited metallic vapors, but as having also bright lines and bands superposed on the background of continuous spectrum. Such a conception not only opens the way to the discovery of others of the non-metals, sulphur, phosphorus, selenium, chlorine, bromine, iodine, fluorine, carbon, etc., but also may account for some of the so-called dark lines, by regarding them as intervals between bright lines."
SEELYE ON CIVILIZATION AND RELIGION.
The inaugural address of Prof. J. H. Seelye, upon assuming the presidency of Amherst College, has attracted the marked attention that was to have been expected from the eminent scholarship and versatile accomplishments of the author. The interest, moreover, has been especially heightened by the intrepidity evinced in his choice of a subject. President Seelye did not shrink from the responsibilities of the occasion. Taking the helm of a leading orthodox institution for the education of young men, founded we are told "as a breakwater to Harvard, which had been captured by Unitarianism," and, therefore, as a bulwark of evangelical faith, he addressed himself to one of the great vital issues which have been forced upon modern theology and made prominent by the later advances of scientific thought. His subject is the relations of religion to civilization and to education.
President Seelye's argument has been interpreted as an assault upon the doctrine of evolution, and by his admirers as an annihilation of it. The Christian Intelligencer, for example, says, "It has fallen like a bomb into the camps of skepticism;" and has a startling significance "in this day of theological enervation and cowardice before a dogmatic evolutionism." Again, the writer says: "He first of all joins issue with the superficial and unsupported notion that there is 'an inherent law of progress in human nature by which it is constantly seeking and gaining for itself an improved condition,' and contends, on the contrary, that there is a 'law of deterioration.' Most acutely and eloquently does he prick this bubble, blown of sentimentalism and conceit, which has so long been suffered to pass unchallenged, and even been hastily adopted by Christian thinkers."
Now, with this estimate of the address we can hardly agree. If evolutionism be a bubble, we doubt if it has been reserved for President Seelye to prick it; and if the address be a bombshell, there are grounds for thinking that it is the president's own party that must beware of the explosion. His positions are: 1. That the historic phenomena of national decay disprove the doctrine of evolution; 2. That whatever progress there has been is due to the supernatural. He says:
"No historical fact is clearer than that human progress has never revealed any inherent power of self-perpetuation. Arts, languages, literature, sciences, civilizations, religions, have in unnumbered instances deteriorated and left a people to grope in the shadow of death whose progenitors seem to rejoice in the light of life."
"It was not the construction of his house that taught man to build his temple, but exactly the other way. The same is true with sculpture, painting, poetry, and music. It was a religious impulse which gave to all these their first inspiration. The oldest monuments we possess of any of these arts are associated with some religious rite or faith. But, more than this, we must also notice the undoubted fact that the arts have grown in glory just as the religious sentiment has grown in power."
"The supernatural is the Alpha as well as the Omega of human thought."
These are favorite ideas with President Seelye, which he has expounded elsewhere, and we shall perhaps get his view more sharply before us by quoting briefly from an earlier statement, also made with deliberate care. In the article on "Darwinism," in "Johnson's New Universal Cyclopædia," he says:
"The history of men is full of instances of deterioration. If we weigh it simply by number, whether of years, or of nations, or of individuals, degeneration and decay vastly preponderate. Where is the civilization now of Tyre, and Carthage, and Babylon, and Nineveh? and where are the arts which built the Great Pyramid and Baalbec? All over the world we have evidence of a tendency among nations and men to sink away from civilization into barbarism, but history does not show an instance of a nation rising by its own efforts from barbarism to civilization. . . . The incontestable fact is, that human nature reveals no inherent impulse to improve or perfect itself. History gives unnumbered cases of a downward tendency, but not a single instance of a self-evolved progress. The lamp which lights one nation in its advancement has been always lighted by a lamp behind it. Civilization is never indigenous; it is an exotic plant wherever found. This is the simple truth of history, which makes all such discussions as Mr. Darwin's respecting the descent of man as false to fact as they are abhorrent to philosophy."
President Seelye's inference that because nations decay there is no evolution of humanity, does not appear to be conclusive. The considerations alleged as making the doctrine of Darwin's discussions "false to fact" seem to us to be in harmony with it, and the natural consequence of it. President Seelye appeals to the historic phenomena of deterioration, disintegration, and decay among nations and civilizations as disproving the principle of development; but how is decay made possible except by previous growth, and how can a community degenerate unless it has first been organized and unfolded? The conclusion is certainly logical that before civilizations can dissolve they must first be evolved, so that to affirm a "law of deterioration" is necessarily to imply a previous "law of evolution." In the normal course of Nature the effete and outworn must pass away. The spent molecules of our tissues have to be eliminated, that more vitalized particles may replace them. Individuals when they get old and useless die out of the community, that their younger and more vigorous successors may carry on the work. On the larger scale, but in the same way, nations die out as civilization progresses; while civilizations themselves are spent in the larger advancement of humanity. We may brood with morbid sentiment over excretion, decay, and death, until there seems to be nothing else; yet these are normal things, and are simply the correlates and the consequences of growth and life. President Seelye declares that in the past career of humanity "degeneration and decay vastly preponderate;" he should have explained how that can be—how there could be a fall without a previous rise to make it possible. If he means that much the greater number of nations and civilizations come apparently to naught, we have simply to say that this is the law in the realm of life: the eggs that are wasted and the seeds that are scattered and lost vastly preponderate over those that mature. Nature is profuse in the waste of life, and sacrifices multitudes where but few are perfected. But is not this ruthless and wide-spread destruction only a part of Nature's policy for the attainment of grand results? The evolutionists affirm continuity of influence in the sphere of life, and that some of the nations and civilizations which decline and die pass on the impulses which they have gained to reappear in succeeding and higher stages of national and racial development. President Seelye recognizes this principle of continuity in saying, "The lamp which lights one nation in its advancement has been always lighted by a lamp behind it." National advancement is here conceded, and also a series of advancements, each depending upon a preceding one. But is there nothing gained by accumulated experience? Is there no general progress resulting from the advancement of nations in succession and under different circumstances? If the dissolution of states and the decay of civilizations do not break the continuity of those agencies by which man is civilized, how can they hinder that gradual improvement of the process and heightening of the effects which evolution implies as the consequence of prolonged, varied, and accumulated national experiences?
If we try President Seelye's logic in a more special case, its quality will, perhaps, be more apparent. "Behold," he might say, "the orchards of the world! They deteriorate and decay, and nothing remains of them at last but withered branches, dead trunks, and rotten stumps. Where are the orchards mentioned by Pliny, the orchards of the middle ages, the old Indian orchards, or even the orchards of the Revolution? The history of apples does not show an instance of an orchard growing by its own efforts. The vitality which impels one orchard in its growth has always been kindled from the vitality of an orchard behind it. This is the simple truth of history, which makes all such discussions as Mr. Darwin's respecting the descent of the golden pippin from the sour and miserable crab as false to fact as they are abhorrent to pomology."
In regard to the second and main position of President Seelye's address respecting the relations of religion to civilization, it is chiefly interesting from the indications it affords of the rationalistic tendencies of New England orthodoxy. We by no means object to the prominent part which he assigns to religion in promoting the progress of man; and are only agreeably surprised at the catholicity of his position. The president says that "human nature reveals no internal impulse to improve and perfect itself;" this he maintains is due to an external impulse, to a power above man, which he assumes to be the agency of supernatural religion. But the transition from barbarism to civilization has taken place on an extensive scale. President Seelye asks, "Where are now the civilizations of Tyre and Carthage, of Nineveh and Babylon?" His question implies that they once existed, and his hypothesis of their origin is that they were the product of religious inspiration and supernatural agency. It will be hardly claimed that those ancient and extinct civilizations were due to the Christian religion; but if not, then they were caused by other religions potent with genuine inspirations and supernatural in their elevating influence. Yet is it not the essence of orthodoxy that it is the only true faith, and that all other so-called religions are delusions, impostures, and heathenish superstitions? The implication of the inaugural address contravenes evangelical theology by assuming that there are other religions than that professed in New England, which are genuinely attested as of supernatural influence by their civilizing impulses, and which have been in operation whenever and wherever there has been any improvement in the condition of humanity. Now, this recognition of the universality of genuine religious influences, as opposed to the exclusive claims of any particular system, we understand to be the broad ground of rationalism; and, if Amherst orthodoxy can accept it, we shall certainly be the last to complain. We only hope, however, that this surrender, horse, foot, and dragoons, to ultra-rationalism, is not to be considered as a bomb-shell in the camp of evolution.
It is a serious question whether President Seelye has not here put a strain upon the claims of supernaturalism which endangers them. Granting the universality of the religious agency, he must explain why it is not always efficient in the work of elevation. The president points impressively to the phenomena of national degeneracy and decay. Viewed as a part of the order of Nature, these phenomena are explicable; but, from President Seelye's point of view, what reason is there why all that had been gained should be thus thrown away? His theory that true religious influences are coextensive with all phases of human progress is an important step in the liberal direction; and his further assumption that the rhythmic successions of progress are due to an intermittent supernaturalism can have little other tendency than to eliminate the supernatural from the investigation of the subject. Why should President Seelye stop half-way, and, having taken latitudinarian ground in regard to the extent of true religious influences, why should he not complete the work of rationalization by recognizing the religious element as a necessary and indestructible part of the constitution of human nature?
The question of the agencies by which man has been civilized or failed to become so, and which determine his present advancement or retrogression, involves forces which do not belong to an imaginary sphere of mystical caprice, but to the orderly course of natural things which it is the proper office of Science to explore. The religious agency must submit to this ordeal, and be dispassionately studied in its laws of action in connection with and in the same way as all the other agencies which enter into the great result, and which are just as divinely ordained as that to which theologians are wont to ascribe everything, and of which they claim to be the special guardians. President Seelye reechoes the old assumption, although in a manner which shows how far his law of decay has already taken effect upon orthodoxy under the liberalizing influence of Science. But if the reader desires to obtain a better idea of the progress that the scientific method has really made in its application to the study of civilization, and to contrast its results with those of preceding methods, let him carefully read the opening article of the magazine in his hand.