Louis Agassiz: His Life and Correspondence Part 17

Humboldt writes him not without anxiety lest his determination to complete all the tasks he had undertaken, including the Nomenclator, should involve him in endless delays and perplexities.

HUMBOLDT TO AGa.s.sIZ.

BERLIN, September 16, 1845.

. . .Your Nomenclator frightens me with its double entries. The Milky Way must have crossed your path, for you seem to be dealing with nebulae which you are trying to resolve into stars. For pity's sake husband your strength. You treat this journey as if it were for life. As to finis.h.i.+ng,--alas! my friend, one does not finish.

Considering all that you have in your well-furnished brain beside your acc.u.mulated papers, half the contents of which you do not yourself know, your expression "aufraumen,"--to put in final order, is singularly inappropriate. There will always remain some burdensome residue,--last things not yet accounted for. I beg you, then, not to abuse your strength. Be content to finish only what seems to you nearest completion,--the most advanced of your work.

Your letter reached me, unaccompanied, however, by the books it announces. They are to come, no doubt, in some other way. Spite of the demands made upon me by the continuation of my "Cosmos," I shall find time to read and profit by your introduction to the Old Red. I am inclined to sing hymns of praise to the Hyperboreans who have helped you in this admirable work. What you say of the specific difference in vertical line and of the increased number of biological epochs is full of interest and wisdom. No wonder you rebel against the idea that the Baltic contains microscopic animals identical with those of the chalk! I foresee, however, a new battle of Waterloo between you and my friend Ehrenberg, who accompanied me lately, just after the Victoria festivals, to the volcanoes of the Eifel with Dechen. Not an inch of ground without infusoria in those regions! For Heaven's sake do not meddle with the infusoria before you have seen the Canada Lakes and completed your journey. Defer them till some more tranquil period of your life. . .I must close my letter with the hope that you will never doubt my warm affection. a.s.suredly I shall find no fault with any course of lectures you may give in the new world, nor do I see the least objection to giving them for money. You can thus propagate your favorite views and spread useful knowledge, while at the same time you will, by most honorable and praiseworthy means, provide additional funds for your traveling expenses. . .

The following correspondence with Professor Adam Sedgwick is of interest, as showing his att.i.tude and that of Aga.s.siz toward questions which have since acquired a still greater scientific importance.

PROFESSOR ADAM SEDGWICK TO LOUIS AGa.s.sIZ.

TRINITY COLLEGE, CAMBRIDGE, April 10, 1845.

MY DEAR PROFESSOR,

The British a.s.sociation is to meet here about the middle of June, and I trust that the occasion will again bring you to England and give me the great happiness of entertaining you in Trinity College.

Indeed, I wish very much to see you; for many years have now elapsed since I last had that pleasure. May G.o.d long preserve your life, which has been spent in promoting the great ends of truth and knowledge! Your great work on fossil fishes is now before me, and I also possess the first number of your monograph upon the fishes of the Old Red Sandstone. I trust the new numbers will follow the first in rapid succession. I love now and then to find a resting-place; and your works always give me one. The opinions of Geoffroy St. Hilaire and his dark school seem to be gaining some ground in England. I detest them, because I think them untrue. They shut out all argument from DESIGN and all notion of a Creative Providence, and in so doing they appear to me to deprive physiology of its life and strength, and language of its beauty and meaning. I am as much offended in taste by the turgid mystical bombast of Geoffroy as I am disgusted by his cold and irrational materialism.

When men of his school talk of the elective affinity of organic types, I hear a jargon I cannot comprehend, and I turn from it in disgust; and when they talk of spontaneous generation and trans.m.u.tation of species, they seem to me to try nature by an hypothesis, and not to try their hypothesis by nature. Where are their facts on which to form an inductive truth? I deny their starting condition. "Oh! but" they reply, "we have progressive development in geology." Now, I allow (as all geologists must do) a KIND OF PROGRESSIVE DEVELOPMENT. For example, the first fish are below the reptiles; and the first reptiles older than man. I say, we have successive forms of animal life adapted to successive conditions (so far, proving design), and not derived in natural succession in the ordinary way of generation. But if no single fact in actual nature allows us to suppose that the new species and orders were produced successively in the natural way, how did they begin? I reply, by a way out of and above common known, material nature, and this way I call CREATION. Generation and creation are two distinct ideas, and must be described by two distinct words, unless we wish to introduce utter confusion of thought and language. In this view I think you agree with me; for I spoke to you on the subject when we met (alas, TEN years since!) at Dublin.

Would you have the great kindness to give me your most valuable opinion on one or two points?

(1.) Is it possible, according to the known laws of actual nature, or is it probable, on any a.n.a.logies of nature, that the vast series of fish, from those of the Ludlow rock and the Old Red Sandstone to those of our actual seas, lakes, and rivers, are derived from one common original low type, in the way of development and by propagation or natural breeding? I should say, NO. But my knowledge is feeble and at second-hand. Yours is strong and from the fountain-head.

(2.) Is the organic type of fish higher now than it was during the carboniferous period, when the Sauroids so much abounded? If the progressive theory of Geoffroy be true, in his sense, each cla.s.s of animals ought to be progressive in its organic type. It appears to me that this is not true. Pray tell me your own views on this point.

(3.) There are "ODD FISH" (as we say in jest) in the Old Red Sandstone. Do these so graduate into crustaceans as to form anything like such an organic link that one could, by generation, come naturally from the other? I should say, NO, being instructed by your labors. Again, allowing this, for the sake of argument, are there not much higher types of fish which are contemporaneous with the lower types (if, indeed, they be lower), and do not these n.o.bler fish of the Old Red Sandstone stultify the hypothesis of natural generative development?

(4.) Will you give me, in a few general words, your views of the scale occupied by the fish of the Old Red, considered as a natural group? Are they so rudimentary as to look like abortions or creatures derived from some inferior cla.s.s, which have not yet by development reached the higher type of fish? Again, I should say, NO; but I long for an answer from a great authority like yours. I am most anxious for a good general conception of the fish of the Old Red, with reference to some intelligible scale.

(5.) Lastly, is there the shadow of ground for supposing that by any natural generative development the Ichthyosaurians and other kindred forms of reptile have come from Sauroid, or any other type of fish? I believe you will say, NO. At any rate, the facts of geology lend no support to such a view, for the n.o.bler forms of Reptile appear in strata below those in which the Ichthyosaurians, etc., are first seen. But I must not trouble you with more questions. Professor Whewell is now Master of Trinity College. We shall all rejoice to see you.

Ever, my dear Professor, your most faithful and most grateful friend,

A. SEDGWICK.

FROM LOUIS AGa.s.sIZ TO A. SEDGWICK.

NEUCHATEL, June, 1845.

. . .I reproach myself for not acknowledging at once your most interesting letter of April 10th. But you will easily understand that in the midst of the rush of work consequent upon my preparation for a journey of several years' duration I have not noticed the flight of time since I received it, until to-day, when the sight of the date fills me with confusion. And yet, for years, I have not received a letter which has given me greater pleasure or moved me more deeply. I have felt in it and have received from it that vigor of conviction which gives to all you say or write a virile energy, captivating alike to the listener or the reader.

Like you, I am pained by the progress of certain tendencies in the domain of the natural sciences; it is not only the arid character of this philosophy of nature (and by this I mean, not NATURAL PHILOSOPHY, but the "Natur-philosophie" of the Germans and French) which alarms me. I dread quite as much the exaggeration of religious fanaticism, borrowing fragments from science, imperfectly or not at all understood, and then making use of them to prescribe to scientific men what they are allowed to see or to find in Nature. Between these two extremes it is difficult to follow a safe road. The reason is, perhaps, that the domain of facts has not yet received a sufficiently general recognition, while traditional beliefs still have too much influence upon the study of the sciences.

Wis.h.i.+ng to review such ideas as I had formed upon these questions, I gave a public course this winter upon the plan of creation as shown in the development of the animal kingdom. I wish I could send it to you, for I think it might please you. Unhappily, I had no time to write it out, and have not even an outline of it. But I intend to work further upon this subject and make a book upon it one of these days. If I speak of it to-day it is because in this course I have treated all the questions upon which you ask my opinion. Let me answer them here after a somewhat aphoristic fas.h.i.+on.

I find it impossible to attribute the biological phenomena, which have been and still are going on upon the surface of our globe, to the simple action of physical forces. I believe they are due, in their entirety, as well as individually, to the direct intervention of a creative power, acting freely and in an autonomic way. . .I have tried to make this intentional plan in the organization of the animal kingdom evident, by showing that the differences between animals do not const.i.tute a material chain, a.n.a.logous to a series of physical phenomena, bound together by the same law, but present themselves rather as the phases of a thought, formulated according to a definite aim. I think we know enough of comparative anatomy to abandon forever the idea of the transformation of the organs of one type into those of another. The metamorphoses of certain animals, and especially of insects, so often cited in support of this idea, prove, by the fixity with which they repeat themselves in innumerable species, exactly the contrary. In the persistency of these metamorphoses, distinct for each species and known to repeat themselves annually in a hundred thousand species, and to have done so ever since the present order of things was established on the earth, have we not the most direct proof that the diversity of types is not due to external natural influences? I have followed this idea in all the types of the animal kingdom. I have also tried to show the direct intervention of a creative power in the geographical distribution of organized beings on the surface of the globe when the species are definitely circ.u.mscribed. As evidence of the fixity of generic types and the existence of a higher and free causal power, I have made use of a method which appears to me new as a process of reasoning. The series of reptiles, for instance, in the family of lizards, shows apodal forms, forms with rudimentary feet, then with a successively larger number of fingers until we reach, by seemingly insensible gradations, the genera Anguis, Ophisaurus, and Pseudopus, the Chamosauria, Chirotes, Bipes, Sepo, Scincus, and at last the true lizards. It would seem to any reasonable man that these types are the transformations of a single primitive type, so closely do the modifications approach each other; and yet I now reject any such supposition, and after having studied the facts most thoroughly, I find in them a direct proof of the creation of all these species. It must not be forgotten that the genus Anguis belongs to Europe, the Ophisaurus to North America, the Pseudopus to Dalmatia and the Caspian steppe, the Sepo to Italy, etc. Now, I ask how portions of the earth so absolutely distinct could have combined to form a continuous zoological series, now so strikingly distributed, and whether the idea of this development could have started from any other source than a creative purpose manifested in s.p.a.ce? These same purposes, this same constancy in the employment of means toward a final end, may be read still more clearly in the study of the fossils of the different creations. The species of all the creations are materially and genealogically as distinct from each other as those of the different points on the surface of the globe. I have compared hundreds of species reputed identical in various successive deposits,--species which are always quoted in favor of a transition, however indirect, from one group of species to another, --and I have always found marked specific differences between them.

In a few weeks I will send you a paper which I have just printed on this subject, where it seems to me this view is very satisfactorily proved. The idea of a procreation of new species by preceding ones is a gratuitous supposition opposed to all sound physiological notions. And yet it is true that, taken as a whole, there is a gradation in the organized beings of successive geological formations, and that the end and aim of this development is the appearance of man. But this serial connection of all successive creatures is not material; taken singly these groups of species show no relation through intermediate forms genetically derived one from the other. The connection between them becomes evident only when they are considered as a whole emanating from a creative power, the author of them all. To your special questions I may now very briefly reply.

Have fishes descended from a primitive type? So far am I from thinking this possible, that I do not believe there is a single specimen of fossil or living fish, whether marine or fresh-water, that has not been created with reference to a special intention and a definite aim, even though we may be able to detect but a portion of these numerous relations and of the essential purpose.

Are the present fishes superior to the older ones? As a general proposition, I would say, NO; it seems to me even that the fishes which preceded the appearance of reptiles in the plan of creation were higher in certain characters than those which succeeded them; and it is a strange fact that these ancient fishes have something a.n.a.logous with reptiles, which had not then made their appearance.

One would say that they already existed in the creative thought, and that their coming, not far removed, was actually antic.i.p.ated.

Can the fishes of the Old Red be considered the embryos of those of later epochs? Of course they are the first types of the vertebrate series, including the most ancient of the Silurian system; but they each const.i.tute an independent fauna, as numerous in the places where these earlier fishes are found, as the present fishes in any area of similar extent on our sea-sh.o.r.e to-day. I now know one hundred and four species of fossil fish from the Old Red, belonging to forty-four genera, comprised under seven families, between several of which there is but little a.n.a.logy as to organization. It is therefore impossible to look upon them as coming from one primitive stock. The primitive diversity of these types is quite as remarkable as that of those belonging to later epochs. It is nevertheless true that, regarded as part of the general plan of creation, this fauna presents itself as an inferior type of the vertebrate series, connecting itself directly in the creative thought with the realization of later forms, the last of which (and this seems to me to have been the general end of creation) was to place man at the head of organized beings as the key-stone and term of the whole series, the final point in the premeditated intention of the primitive plan which has been carried out progressively in the course of time. I would even say that I believe the creation of man has closed creation on this earth, and I draw this conclusion from the fact that the human genus is the first cosmopolite type in Nature. One may even affirm that man is clearly announced in the phases of organic development of the animal kingdom as the final term of this series.

Lastly: Is there any reason to believe that the Ichthyosaurians are descendants of the Sauroid fishes which preceded the appearance of these reptiles? Not the least. I should consider any naturalist who would seriously present the question in this light as incapable of discussing it or judging it. He would place himself outside of the facts and would reason from a basis of his own creating. . .

In the "Revue Suisse" of April, 1845, there is a notice of the course of lectures to which reference is made in the above letter.

"A numerous audience a.s.sembled on the 26th of March for the opening of a course by Professor Aga.s.siz on the 'Plan of Creation.' It is with an ever new pleasure that our public come together to listen to this savant, still so young and already so celebrated. Not content with pursuing in seclusion his laborious scientific investigations, he makes a habit of communicating, almost annually, to an audience less restricted than that of the Academy the general result of some of his researches. All the qualities to which Mr.

Aga.s.siz has accustomed his listeners were found in the opening prelude; the fullness and freedom of expression which give to his lectures the character of a scientific causerie; the dignified ease of bearing, joined with the simplicity and candor of a savant who teaches neither by aphorisms nor oracles, but who frankly admits the public to the results of his researches; the power of generalization always based upon a patient study of facts, which he knows how to present with remarkable clearness in a language that all can understand. We will not follow the professor in tracing the outlines of his course. Suffice it to say that he intends to show in the general development of the animal kingdom the existence of a definite preconceived plan, successively carried out; in other words, the manifestation of a higher thought,--the thought of G.o.d.

This creative thought may be studied under three points of view: as shown in the relations which, spite of their manifold diversity, connect all the species now living on the surface of the globe; in their geographical distribution; and in the succession of beings from primitive epochs until the present condition of things."

The summer of 1845 was the last which Aga.s.siz pa.s.sed at home. It was broken by a short and hurried visit to the glacier of the Aar, respecting which no details have been preserved. He did not then know that he was taking a final leave of his cabin among the rocks and ice. Affairs connected with the welfare of the inst.i.tution in Neuchatel, with which he had been so long connected, still detained him for a part of the winter, and he did not leave for Paris until the first week in March, 1846. His wife and daughters had already preceded him to Germany, where he was to join them again on his way to Paris, and where they were to pa.s.s the period of his absence, under the care of his brother-in-law, Mr. Alexander Braun, then living at Carlsruhe. His son was to remain at school at Neuchatel.

It was two o'clock at night when he left his home of so many years.

There had been a general sadness at the thought of his departure, and every testimony of affection and respect accompanied him. The students came in procession with torch-lights to give him a parting serenade, and many of his friends and colleagues were also present to bid him farewell. M. Louis Favre says in his Memoir, "Great was the emotion at Neuchatel when the report was spread abroad that Aga.s.siz was about to leave for a long journey. It is true he promised to come back, but the New World might shower upon him such marvels that his return could hardly be counted upon. The young people, the students, regretted their beloved professor not only for his scientific attainments, but for his kindly disposition, the charm of his eloquence, the inspiration of his teaching; they regretted also the gay, animated, untiring companion of their excursions, who made them acquainted with nature, and knew so well how to encourage and interest them in their studies."

Pausing at Carlsruhe on his journey, he proceeded thence to Paris, where he was welcomed with the greatest cordiality by scientific men. In recognition of his work on the "Fossil Fishes" the Monthyon Prize of Physiology was awarded him by the Academy. He felt this distinction the more because the bearing of such investigations upon experimental physiology had never before been pointed out, and it showed that he had succeeded in giving a new direction and a more comprehensive character to paleontological research. He pa.s.sed some months in Paris, busily occupied with the publication of the "Systeme Glaciaire," his second work on the glacial phenomena. The "Etudes sur les Glaciers" had simply contained a resume of all the researches undertaken upon the Alpine fields of ice and the results obtained up to 1840, inclusive of the author's own work and his wider interpretation of the facts. The "Systeme Glaciaire" was, on the contrary, an account of a connected plan of investigation during a succession of years, upon a single glacier, with its geodetic and topographic features, its hydrography, its internal structure, its atmospheric conditions, its rate of annual and diurnal progress, and its relations to surrounding glaciers. All the local phenomena, so far as they could be observed, were subjected to a strict scrutiny, and the results corrected by careful comparison, during five seasons. As we have seen, and as Aga.s.siz himself says in his Preface, this band of workers had "lived in the intimacy of the glacier, striving to draw from it the secret of its formation and its annual advance." The work was accompanied by three maps and nine plates. In such a volume of detail there is no room for picturesque description, and little is told of the wonderful scenes they witnessed by day and night, nothing of personal peril and adventure.

This task concluded, he went to England, where he was to spend the few remaining days previous to his departure. Among the last words of farewell which reached him just as he was leaving the Old World, little thinking then that he was to make a permanent home in America, were these lines from Humboldt, written at Sans Souci: "Be happy in this new undertaking, and preserve for me the first place under the head of friends.h.i.+p in your heart. When you return I shall be here no more, but the king and queen will receive you on this 'historic hill' with the affection which, for so many reasons, you merit. . ."

"Your illegible but much attached friend,

"A. HUMBOLDT."

So closed this period of Aga.s.siz's life. The next was to open in new scenes, under wholly different conditions. He sailed for America in September, 1846.

PART 2.

IN AMERICA.

CHAPTER 13.

1846: AGE 39.

Arrival at Boston.

Previous Correspondence with Charles Lyell and Mr. John A. Lowell concerning Lectures at the Lowell Inst.i.tute.

Relations with Mr. Lowell.

First Course of Lectures.

Character of Audience.

Home Letter giving an Account of his first Journey in the United States.

Impressions of Scientific Men, Scientific Inst.i.tutions and Collections.

AGa.s.sIZ arrived in Boston during the first week of October, 1846.

He had not come to America without some prospect of employment beside that comprised in his immediate scientific aims. In 1845, when his plans for a journey in the United States began to take definite shape, he had written to ask Lyell whether, notwithstanding his imperfect English, he might not have some chance as a public lecturer, hoping to make in that way additional provision for his scientific expenses beyond the allowance he was to receive from the King of Prussia. Lyell's answer, written by his wife, was very encouraging.