LOUIS AGASSIZ TO THE PRINCE OF CANINO.

GLACIER OF THE AAR, September 1, 1842.

. . .I thank you most sincerely for the pains you have so kindly taken with my proof, and for pointing out the faults and omissions you have noticed in my register of birds. I made the corrections at once, and have taken the liberty of mentioning on the cover of this number the share you have consented to take in my Nomenclator. I shall try to do better and better in the successive classes, but you well know the impossibility of avoiding grave errors in such a work, and that they can be wholly weeded out only in a second and third edition. I should have written sooner in answer to your last, had not your letter reached me on the Glacier of the Aar, where I have been since the beginning of July, following up observations, the results of which become every day more important and more convincing. The most striking fact, one which I think I have placed beyond the reach of doubt, is the primitive stratification of the neve, or fields of snow,--stratified from the higher regions across the whole course of the glacier to its lower extremity. I have prepared a general map, with transverse sections, showing how the layers lift themselves on the borders of the glacier and also at their junction, where two glaciers meet at the outlet of adjoining valleys; and how, also, the waving lines formed by the layers on the surface change to sharper concentric curves with a marked axis, as the glacier descends to lower levels. For a full demonstration of the matter, I ought to send you my map and plans, of which I have, as yet, no duplicates; but the fact is incontestable, and you will oblige me by announcing it in the geological section at Padua. M. Charpentier, who is going to your meeting, will contest it, but you can tell him from me that it is as evident as the stratification of the Neptunic rocks. To see and understand it fully, however, one must stand well above the glacier, so as to command the surface as a whole in one view. I would add that I am not now alluding to the blue and white bands in the ice of which I spoke to you last year; this is a quite distinct phenomenon.

I wish I could accept your kind invitation, but until I have gone to the bottom of the glacier question and terminated my "Fossil Fishes," I do not venture to move. It is no light task to finish all this before our long journey, to which I look forward, as it draws nearer, with a constantly increasing interest. I am very sorry not to join you at Florence. It would have been a great pleasure for me to visit the collections of northern Italy in your company. . .I write you on a snowy day, which keeps me a prisoner in my tent; it is so cold that I can hardly hold my pen, and the water froze at my bedside last night. The greatest privation is, however, the lack of fruit and vegetables. Hardly a potato once a fortnight, but always and every day, morning and night, mutton, everlasting mutton, and rice soup. As early as the end of July we were caught for three days by the snow; I fear I shall be forced to break up our encampment next week without having finished my work. What a contrast between this life and that of the plain! I am afraid my letter may be long on the road before reaching the mail, and I pause here that I may not miss the chance of forwarding it by a man who has just arrived with provisions and is about to return to the hospice of the Grimsel, where some trustworthy guide will undertake to deliver it at the first post-office.

No sooner is Agassiz returned from the glacier than we meet him again in the domain of his fossil fishes.

LOUIS AGASSIZ TO SIR PHILIP EGERTON.

NEUCHATEL, December 15, 1842.

. . .In the last few months I have made an important step in the identification of fossil fishes. The happy idea occurred to me of applying the microscope to the study of fragments of their bones, especially those of the head, and I have found in their structure modifications as remarkable and as numerous as those which Mr. Owen discovered in the structure of teeth. Here there is a vast new field to explore. I have already applied it to the identification of the fossil fishes in the Old Red of Russia sent me for that purpose by Mr. Murchison. You will find more ample details about it in my report to him. I congratulate myself doubly on the results; first, because of their great importance in paleontology, and also because they will draw more closely my relations with Mr. Owen, whom I always rejoice to meet on the same path with myself, and whom I believe incapable of jealousy in such matters. . .The only point indeed, on which I think I may have a little friendly difference with him, is concerning the genus Labyrinthodon, which I am firmly resolved, on proofs that seem to me conclusive, to claim for the class of fishes.* (* On seeing Owen's evidence some years later, Agassiz at once acknowledged himself mistaken on this point. ) As soon as I have time I will write to Mr. Owen, but this need not prevent you from speaking to him on the subject if you have an early opportunity to do so. I am now exclusively occupied with the fossil fishes, which at any cost I wish to finish this winter. . . Before even returning to my glacier work, I will finish my monograph of the Old Red, so that you may present it at the Cork meeting, which it will be impossible for me to attend. . .I am infinitely grateful to you and Lord Enniskillen for your willingness to trust your Sheppy fishes to me; I shall thus be prepared in advance for a strict determination of these fossils. Having them for some time before my eyes, I shall become familiar with all the details. When I know them thoroughly, and have compared them with the collections of skeletons in the Museums of Paris, of Leyden, of Berlin, and of Halle, I will then come to England to see what there may be in other collections which I cannot have at my disposal here.

The winter of 1843, apart from his duties as professor, was devoted to the completion of the various zoological works on which he was engaged, and to the revision of materials he had brought back from the glacier. His habits with reference to physical exercise were very irregular. He passed at once from the life of the mountaineer to that of the closet student. After weeks spent on the snow and ice of the glacier, constantly on foot and in the open air, he would shut himself up for a still longer time in his laboratory, motionless for hours at his microscope by day, and writing far into the night, rarely leaving his work till long after midnight. He was also forced at this time to press forward his publications in the hope that he might have some return for the sums he had expended upon them. This was indeed a very anxious period of his life. He could never be brought to believe that purely intellectual aims were not also financially sound, and his lithographic establishment, his glacier work, and his costly researches in zoology had proved far beyond his means. The prophecies of his old friend Humboldt were coming true. He was entangled in obligations, and crushed under the weight of his own undertakings. He began to doubt the possibility of carrying out his plan of a scientific journey to the United States.

AGASSIZ TO THE PRINCE OF CANINO.

NEUCHATEL, April, 1843.

. . .I have worked like a slave all winter to finish my fossil fishes; you will presently receive my fifteenth and sixteenth numbers, forwarded two days since, with more than forty pages of text, containing many new observations. I shall allow myself no interruption until this work is finished, hoping thereby to obtain a little freedom, for if my position here is not changed I shall be forced to seek the means of existence elsewhere. Meantime, extravagant projects present themselves, as is apt to be the case when one is in difficulties. That of accompanying you to the United States was so tempting, that I am bitterly disappointed to think that its execution becomes impossible in my present circumstances. All my projects for further publications must also be adjourned, or perhaps renounced. . .Possibly, when my work on the fossil fishes is completed, the sale of some additional copies may help me to rise again. And yet I have not much hope of this, since all the attempts of my friends to obtain subscriptions for me in France and Russia have failed: because the French government takes no interest in what is done out of Paris; and in Russia such researches, having little direct utility, are looked upon with indifference. Do you think any position would be open to me in the United States, where I might earn enough to enable me to continue the publication of my unhappy books; which never pay their way because they do not meet the wants of the world?. . .

In the following July we find him again upon the glacier. But the campaign of 1843 opened sadly for the glacial party. Arriving at Meiringen they heard that Jacob Leuthold was ill and would probably be unable to accompany them. They went to his house, and found him, indeed, the ghost of his former self, apparently in a rapid decline. Nevertheless, he welcomed them gladly to his humble home, and would have kept them for some refreshment. Fearing to fatigue him, however, they stayed but a few moments. As they left, one of the party pointed to the mountains, adding a hope that he might soon join them. His eyes filled with tears; it was his only answer, and he died three days later. He was but thirty-seven years of age, and at that time the most intrepid and the most intelligent of the Oberland guides. His death was felt as a personal grief by the band of workers whose steps he had for years guided over the most difficult Alpine passes.

The summer's work continued and completed that of the last season. On leaving the glacier the year before they had marked a network of loose boulders, such as travel with the ice, and also a number of fixed points in the valley walls, comparing and registering their distance from each other. They had also sunk a line of stakes across the glacier. The change in the relative position of the two sets of signals and the curve in their line of stakes gave them, self-recorded, as it were, the rate of advance of the glacier as a whole, and also the comparative rate of progression in its different parts. Great pains was also taken during the summer to measure the advance in every twenty-four hours, as well as to compare the diurnal with the nocturnal movement, and to ascertain the amount of surface waste. The season was an unfavorable one, beginning so late and continuing so cold that the period of work was shortened.

CHAPTER 12.

1843-1846: AGE 36-39.

Completion of Fossil Fishes. Followed by Fossil Fishes of the Old Red Sandstone. Review of the Later Work. Identification of Fishes by the Skull. Renewed Correspondence with Prince Canino about Journey to the United States. Change of Plan owing to the Interest of the King of Prussia in the Expedition. Correspondence between Professor Sedgwick and Agassiz on Development Theory. Final Scientific Work in Neuchatel and Paris. Publication of "Systeme Glaciaire."