Louis Agassiz: His Life and Correspondence

by Louis Agassiz

. . .I cannot express to you my pleasure in reading your letter of May 10th (which was, unhappily, only delivered to me on my passage through Carlsruhe, at the end of July). . .To know that I have occupied your thoughts a moment, especially in days of trial and sorrow such as you have had to bear, raises me in my own eyes, and redoubles my hope for the future. And just now such encouragement is particularly cheering under the difficulties which I meet in completing my task in England. I have now been here nearly two months, and I hope before leaving to finish the description of all that I brought together at the Geological Society last year. Knowing that you are in Paris, however, I cannot resist the temptation of going to see you; indeed, should your stay be prolonged for some weeks, it would be my most direct path for home. I should like to tell you a little of what I have done, and how the world has gone with me since we last met. . .I have certainly committed an imprudence in throwing myself into an enterprise so vast in proportion to my means as my "Fossil Fishes." But, having begun it, I have no alternative; my only safety is in success. I have a firm conviction that I shall bring my work to a happy issue, though often in the evening I hardly know how the mill is to be turned to-morrow. . .

By a great good fortune for me, the British Association, at the suggestion of Buckland, Sedgwick, and Murchison, has renewed, for the present year, its vote of one hundred guineas toward the facilitating of researches upon the fossil fishes of England, and I hope that a considerable part of this sum may be awarded to me, in which case I may be able to complete the greater number of the drawings I need. If I had obtained in France only half the subscriptions I have had in England, I should be afloat; but thus far M. Bailliere has only disposed of some fifteen copies. . .My work advances fairly; I shall soon have described all the species I know, numbering now about nine hundred. I need some weeks in Paris for the comparison of several tertiary species with living ones in order to satisfy myself of their specific identity, and then my task will be accomplished. Next comes the putting in order of all my notes. My long vacations will give me time to do this with the greatest care. . .

His second visit to England, during which the above letter was written, was chiefly spent in reviewing the work of his artist, whom he now reinforced with a second draughtsman, M. Weber, the same who had formerly worked with him in Munich. He also attended the meeting of the British Association in Dublin, stayed a few days at Oulton Park for another look at the collections of Sir Philip Egerton, made a second grand tour among the other fossil fishes of England and Ireland, and returned to Neuchatel, leaving his two artists in London with their hands more than full.

While Agassiz thus pursued his work on fossil fishes with ardor and an almost perilous audacity, in view of his small means, he found also time for various other investigations. During the year 1836, though pushing forward constantly the publication of the "Poissons Fossiles," his "Prodromus of the Class of Echinodermata" appeared in the Memoirs of the Natural History Society of Neuchatel, as well as his paper on the fossil Echini belonging to the Neocomian group of the Neuchatel Jura, accompanied by figures. Not long after, he published in the Memoirs of the Helvetic Society his descriptions of fossil Echini peculiar to Switzerland, and issued also the first number of a more extensive work, "Monographie d'Echinodermes." During this year he received a new evidence of the sympathy of the English naturalists, in the Wollaston medal awarded to him by the London Geological Society.

The summer of 1836 was an eventful one for Agassiz,—the opening, indeed, of a new and brilliant chapter in his life. The attention of the ignorant and the learned had alike been called to the singular glacial phenomena of movement and transportation in the Alpine valleys. The peasant had told his strange story of boulders carried on the back of the ice, of the alternate retreat and advance of glaciers, now shrinking to narrower limits, now plunging forward into adjoining fields, by some unexplained power of expansion and contraction. Scientific men were awake to the interest of these facts, but had considered them only as local phenomena. Venetz and Charpentier were the first to detect their wider significance. The former traced the ancient limits of the Alpine glaciers as defined by the frame-work of debris or loose material they had left behind them; and Charpentier went farther, and affirmed that all the erratic boulders scattered over the plain of Switzerland and on the sides of the Jura had been thus distributed by ice and not by water, as had been supposed.

Agassiz was among those who received this hypothesis as improbable and untenable. Still, he was anxious to see the facts in place, and Charpentier was glad to be his guide. He therefore passed his vacation, during this summer of 1836, at the pretty town of Bex, in the valley of the Rhone. Here he spent a number of weeks in explorations, which served at the same time as a relaxation from his more sedentary work. He went expecting to confirm his own doubts, and to disabuse his friend Charpentier of his errors. But after visiting with him the glaciers of the Diablerets, those of the valley of Chamounix, and the moraines of the great valley of the Rhone and its principal lateral valleys, he came away satisfied that a too narrow interpretation of the phenomena was Charpentier's only mistake.

During this otherwise delightful summer, he was not without renewed anxiety lest he should be obliged to suspend the publication of the Fossil Fishes for want of means to carry it on. On this account he writes from Bex to Sir Philip Egerton in relation to the sale of his original drawings, the only property he possessed. "It is absolutely impossible," he says, "for me to issue even another number until this sale is effected. . .I shall consider myself more than repaid if I receive, in exchange for the whole collection of drawings, simply what I have expended upon them, provided I may keep those which have yet to be lithographed until that be done."

Sir Philip made every effort to effect a sale to the British Museum. He failed at the moment, but the collection was finally purchased and presented to the British Museum by a generous relative of his own, Lord Francis Egerton. In the mean time, Sir Philip and Lord Cole, in order to make it possible for Agassiz to retain the services of Mr. Dinkel, proposed to pay his expenses while he was drawing such specimens from their own collections as were needed for the work. These drawings were, of course, finally to remain their own property.

During his sojourn at Bex, Agassiz's intellect and imagination had been deeply stirred by the glacial phenomena. In the winter of 1837, on his return to Neuchatel, he investigated anew the slopes of the Jura, and found that the facts there told the same story. Although he resumed with unabated ardor his various works on fishes, radiates, and mollusks, a new chapter of nature was all the while unfolding itself in his fertile brain. When the Helvetic Association assembled at Neuchatel in the following summer, the young president, from whom the members had expected to hear new tidings of fossil fishes, startled them by the presentation of a glacial theory, in which the local erratic phenomena of the Swiss valleys assumed a cosmic significance. It is worthy of remark here that the first large outlines in which Agassiz, when a young man, planned his intellectual work gave the key-note to all that followed. As the generalizations on which all his future zoological researches were based, are sketched in the Preface to his "Poissons Fossiles," so his opening address to the Helvetic Society in 1837 unfolds the glacial period as a whole, much as he saw it at the close of his life, after he had studied the phenomena on three continents. In this address he announced his conviction that a great ice-period, due to a temporary oscillation of the temperature of the globe, had covered the surface of the earth with a sheet of ice, extending at least from the north pole to Central Europe and Asia. "Siberian winter," he says, "established itself for a time over a world previously covered with a rich vegetation and peopled with large mammalia, similar to those now inhabiting the warm regions of India and Africa. Death enveloped all nature in a shroud, and the cold, having reached its highest degree, gave to this mass of ice, at the maximum of tension, the greatest possible hardness." In this novel presentation the distribution of erratic boulders, instead of being classed among local phenomena, was considered "as one of the accidents accompanying the vast change occasioned by the fall of the temperature of our globe before the commencement of our epoch."

This was, indeed, throwing the gauntlet down to the old expounders of erratic phenomena upon the principle of floods, freshets, and floating ice. Many well-known geologists were present at the meeting, among them Leopold von Buch, who could hardly contain his indignation, mingled with contempt, for what seemed to him the view of a youthful and inexperienced observer. One would have liked to hear the discussion which followed, in special section, between Von Buch, Charpentier, and Agassiz. Elie de Beaumont, who should have made the fourth, did not arrive till later. Difference of opinion, however, never disturbed the cordial relation which existed between Von Buch and his young opponent. Indeed, Agassiz's reverence and admiration for Von Buch was then, and continued throughout his life, deep and loyal.