As to my collections, I had already thought of asking either the Vaudois government or the city of Neuchatel to receive them into the Museum, merely on condition that they should provide for the expenses of exhibition and preservation, making use of them, meanwhile, for the instruction of the public. I should be sorry to lose all right to them, because I hope they may have another final destination. I do not despair of seeing the different parts of Switzerland united at some future day by a closer tie, and in case of such a union a truly Helvetic university would become a necessity; then, my aim would be to make my collection the basis of that which they would be obliged to found for their courses of lectures. It is really a shame that Switzerland, richer and more extensive than many a small kingdom, should have no university, when some states of not half its size have even two; for instance, the grand duchy of Baden, one of whose universities, that of Heidelberg, ranks among the first in all Germany. If ever I attain a position allowing me so to do, I shall make every effort in my power to procure for my country the greatest of benefits: namely, that of an intellectual unity, which can arise only from a high degree of civilization, and from the radiation of knowledge from one central point.
I, too, have considered the question about Dinkel, and if, when I have finished my work here, my position is not changed, and I have no definite prospect, such as would justify me in keeping him with me,—well! then we must part! I have long been preparing myself for this, by employing him only upon what is indispensable to the publication of my first numbers, hoping that these may procure me the means of paying for such illustrations as I shall further need. As my justification for having engaged him in the first instance, and continued this expense till now, I can truly say that it is in a great degree through his drawings that M. Cuvier has been able to judge of my work, and so has been led to make a surrender of all his materials in my favor. I foresaw clearly that this was my only chance of competing with him, and it was not without reason that I insisted so strongly on having Dinkel with me in passing through Strasbourg and subsequently at Carlsruhe. Had I not done so, M. Cuvier might still be in advance of me. Now my mind is at rest on this score; I have already written you all about his kindness in offering me the work. Could I only be equally fortunate in its publication!
M. Cuvier urges me strongly to present my book to the Academy, in order to obtain a report upon its contents. I must first finish it, however, and the task is not a light one. For this reason, above all, I regret my want of means; but for that I could have the drawings made at once, and the Academy report, considered as a recommendation, would certainly help on the publication greatly. But in this respect I have long been straitened; Auguste knows that I had at Munich an artist who was to complete what I had left there for execution, and that I stopped his work on leaving Concise. If the stagnation of the book-trade continues I shall, perhaps, be forced to give up Dinkel also; for if I cannot begin the publication, which will, I hope, bring me some return, I must cease to accumulate material in advance. Should business revive soon, however, I may yet have the pleasure of seeing all completed before I leave Paris.
I think I forgot to mention the arrival of Braun six weeks after me. I had a double pleasure in his coming, for he brought with him his younger brother, a charming fellow, and a distinguished pupil of the polytechnic school of Carlsruhe. He means to be a mining engineer, and comes to study such collections at Paris as are connected with this branch. You cannot imagine what happiness and comfort I have in my relations with Alexander; he is so good, so cultivated and high-minded, that his friendship is a real blessing to me. We both feel very much our separation from the elder Schimper, who, spite of his great desire to join us at Carlsruhe and accompany us to Paris, was not able to leave Munich. . .
P.S. My love to Auguste. To-day (Sunday) I went again to see M.
Humboldt about Auguste's* (* Concerning a business undertaking in
Mexico.) plan, but did not find him.
Then follow several pages, addressed to his father, in answer to the request contained in one of his last letters that Louis would tell him as much as he thinks he can understand of his work. There is something touching in this little lesson given by the son to the father, as showing with what delight Louis responded to the least touch of parental affection respecting his favorite studies, so long looked upon at home with a certain doubt and suspicion. The whole letter is not given here, as it is simply an elementary treatise on geology; but the close is not without interest as relating to the special investigations on which he was now employed.
"The aim of our researches upon fossil animals is to ascertain what beings have lived at each one of these (geological) epochs of creation, and to trace their characters and their relations with those now living; in one word, to make them live again in our thought. It is especially the fishes that I try to restore for the eyes of the curious, by showing them which ones have lived in each epoch, what were their forms, and, if possible, by drawing some conclusions as to their probable modes of life. You will better understand the difficulty of my work when I tell you that in many species I have only a single tooth, a scale, a spine, as my guide in the reconstruction of all these characters, although sometimes we are fortunate enough to find species with the fins and the skeletons complete. . .
"I ask pardon if I have tired you with my long talk, but you know how pleasant it is to ramble on about what interests us, and the pleasure of being questioned by you upon subjects of this kind has been such a rare one for me, that I have wished to present the matter in its full light, that you may understand the zeal and the enthusiasm which such researches can excite."
To this period belongs a curious dream mentioned by Agassiz in his work on the fossil fishes.* (* "Recherches sur les Poissons Fossiles". Cyclopoma spinosum Agassiz. Volume 4 tab 1, pages 20, 21.) It is interesting both as a psychological fact and as showing how, sleeping and waking, his work was ever present with him. He had been for two weeks striving to decipher the somewhat obscure impression of a fossil fish on the stone slab in which it was preserved. Weary and perplexed he put his work aside at last, and tried to dismiss it from his mind. Shortly after, he waked one night persuaded that while asleep he had seen his fish with all the missing features perfectly restored. But when he tried to hold and make fast the image, it escaped him. Nevertheless, he went early to the Jardin des Plantes, thinking that on looking anew at the impression he should see something which would put him on the track of his vision. In vain,—the blurred record was as blank as ever. The next night he saw the fish again, but with no more satisfactory result. When he awoke it disappeared from his memory as before. Hoping that the same experience might be repeated, on the third night he placed a pencil and paper beside his bed before going to sleep. Accordingly toward morning the fish reappeared in his dream, confusedly at first, but at last with such distinctness that he had no longer any doubt as to its zoological characters. Still half dreaming, in perfect darkness, he traced these characters on the sheet of paper at the bedside. In the morning he was surprised to see in his nocturnal sketch features which he thought it impossible the fossil itself should reveal. He hastened to the Jardin des Plantes, and, with his drawing as a guide, succeeded in chiseling away the surface of the stone under which portions of the fish proved to be hidden. When wholly exposed it corresponded with his dream and his drawing, and he succeeded in classifying it with ease. He often spoke of this as a good illustration of the well-known fact, that when the body is at rest the tired brain will do the work it refused before.