Famous Men of Science Part 25

absence. He left home a high-spirited, warm-hearted youth, fond of athletic sports, and vigorous in body. He came back with a pa.s.sionate love for science, "with the habit of energetic industry and of concentrated attention," but with health impaired, which made the whole of his after life a battle with suffering. Yet he conquered, and gave to his generation a wonderful example of the power of mind over body; of victory over obstacles.

During the voyage he was an almost constant sufferer from sea-sickness.

He wrote home the last year: "It is a lucky thing for me that the voyage is drawing to its close, for I positively suffer more from sea-sickness now than three years ago."

"After perhaps an hour's work," says Admiral Stokes, "he would say to me, 'Old fellow, I must take the horizontal for it,' that being the best relief position from ship motion. A stretch out on one side of the table for some time would enable him to resume his labors for a while, when he had again to lie down. It was distressing to witness this early sacrifice of Mr. Darwin's health, who ever afterwards seriously felt the ill effects of the Beagle's voyage."

Admiral Mellersh says: "I think he was the only man I ever knew against whom I never heard a word said; and as people, when shut up in a ship for five years, are apt to get cross with each other, that is saying a good deal." Says another: "He was never known to be out of temper, or to say one unkind or hasty word _of_ or _to_ any one."

This lovely spirit, which so endeared him to everybody, Darwin kept through life,--a spirit which sheds a halo around every book he wrote, and makes him worthy the admiration and honor of every young man. Many persons have the gift of writing books, but comparatively few persons have the great gift of self-control.

After a brief visit with his family, Darwin hastened to Cambridge, to prepare his "Journal of Travels." He had learned on the Beagle that "a man who dares to waste one hour of time has not discovered the value of life." After three months of hard work, he went to London, where he finished the "Journal," and began working on his "Zoology of the Voyage of the Beagle," and his "Geological Observations." He said at this time: "I have nothing to wish for, excepting stronger health to go on with the subjects to which I have joyfully determined to devote my life."

For three years and eight months he worked untiringly. He wrote Henslow: "I fear the Geology will take me a great deal of time; I was looking over one set of notes, and the quant.i.ty I found I had to read for that one place was frightful. If I live till I am eighty years old I shall not cease to marvel at finding myself an author. In the summer before I started, if any one had told me that I should have been an angel by this time, I should have thought it an equal impossibility. This marvellous transformation is all owing to you."

Darwin and Lyell now became very intimate friends. "I am coming into your way, of only working about two hours at a spell," he writes to Lyell; "I then go out and do my business in the streets, return and set to work again, and thus make two separate days out of one." Of Lyell he said: "One of his chief characteristics was his sympathy with the work of others.... The science of geology is enormously indebted to Lyell--more so, as I believe, than to any other man who ever lived."

The "Journal" was published in 1839. January twenty-nine of this year, Mr. Darwin, now thirty years of age, was married to his cousin, Emma Wedgwood, daughter of Josiah Wedgwood of Maer, and granddaughter of the founder of the potteries of Etruria. The extreme happiness of his married life proved the wisdom of his choice. He said in after years, "No one can be too kind to my dear wife, who is worth her weight in gold many times over."

They lived at No. 12 Upper Gower Street, as he wrote a college mate, "a life of extreme quietness.... We have given up all parties, for they agree with neither of us; and if one is quiet in London, there is nothing like its quietness."

In 1842, his "Structure and Distribution of Coral Reefs" was published, a book which cost him, he says, "twenty months of hard work, as I had to read every work on the islands of the Pacific, and to consult many charts." Of this book, Professor Geikie says: "This well known treatise, the most original of all its author's geological memoirs, has become one of the cla.s.sics of geological literature. The origin of those remarkable rings of coral-rock in mid-ocean has given rise to much speculation, but no satisfactory solution of the problem has been proposed. After visiting many of them, and examining also coral reefs that fringe islands and continents, he offered a theory which, for simplicity and grandeur, strikes every reader with astonishment.... No more admirable example of scientific method was ever given to the world, and, even if he had written nothing else, this treatise alone would have placed Darwin in the very front of investigators of nature."

Lyell wrote to Darwin concerning this book: "It is all true, but do not flatter yourself that you will be believed till you are growing bald, like me, with hard work and vexation at the incredulity of the world."

Darwin's next work, on the "Volcanic Islands Visited during the Voyage of the Beagle," was published in 1844. This book, he said, "cost me eighteen months." His third geological book, "Geological Observations on South America," was published in 1846.

Meantime, tired of smoky London, Darwin purchased a home in Down, a retired village five or six hundred feet above the sea. The house was a square brick building, of three stories, vine-covered, in the midst of eighteen acres. "Its chief merit," Darwin writes to a friend, "is its extreme rurality. I think I was never in a more perfectly quiet country." Here, for forty years, Darwin lived the isolated life of a student, producing the books that made him the most noted scientist of his century. Of these years, Mr. Darwin said: "Few persons can have lived a more retired life than we have done. Besides short visits to the houses of relations, and occasionally to the seaside or elsewhere, we have gone nowhere. During the first part of our residence we went a little into society, and received a few friends here; but my health almost always suffered from the excitement.... I have, therefore, been compelled for many years to give up all dinner parties.... From the same cause I have been able to invite here very few scientific acquaintances.

My chief enjoyment and sole employment throughout life has been scientific work; and the excitement from such work makes me for the time forget, or drives quite away, my daily discomfort."

At Down, Darwin worked for eight years on two large volumes concerning cirripedia (barnacles), describing all the known living species; the extinct species, or fossil cirripedes, were in two smaller volumes. The first books were published by the Ray Society, between 1851 and 1854; the others by the Palaeontographical Society. About two years out of the eight were lost through illness. Sometimes he became half discouraged.

He wrote a friend, "I have been so steadily going downhill, I cannot help doubting whether I can ever crawl a little uphill again. Unless I can, enough to work a little, I hope my life may be very short, for to lie on a sofa all day and do nothing but give trouble to the best and kindest of wives and good, dear children is dreadful."

Darwin doubted, in after life, "whether the work was worth the consumption of so much time," but Professor Huxley thinks he "never did a wiser thing than when he devoted himself to the years of patient toil which the cirriped-book cost him.... The value of the cirriped monograph lies not merely in the fact that it is a very admirable piece of work, and const.i.tuted a great addition to positive knowledge, but still more in the circ.u.mstance that it was a piece of critical self-discipline, the effect of which manifested itself in everything he wrote afterwards, and saved him from endless errors of detail." Darwin's patient labor is shown by his working "for the last half-month, daily, in dissecting a little animal about the size of a pin's head, from the Chonos archipelago, and I could spend another month, and daily see more beautiful structure."

During these years from 1846 to 1854, death had twice disturbed the quiet life at Down. In 1849, Dr. Darwin died, and his son Charles was so ill that he could not attend the funeral. In 1851, Annie Darwin died, at the age of ten, after a brief illness. "She was," said Darwin, "my favorite child; her cordiality, openness, buoyant joyousness, and strong affections made her most lovable.... When quite a baby, this [strong affection] showed itself in never being easy without touching her mother when in bed with her; and quite lately she would, when poorly, fondle for any length of time one of her mother's arms.... She would at almost any time spend half an hour in arranging my hair, 'making it,' as she called it, 'beautiful,' or in smoothing, the poor, dear darling, my collar or cuffs--in short, in fondling me.... Her whole mind was pure and transparent. One felt one knew her thoroughly and could trust her. I always thought that, come what might, we should have had, in our old age, at least one loving soul which nothing could have changed.

"All her movements were vigorous, active, and usually graceful. When going round the Sandwalk with me, although I walked fast, yet she often used to go before, pirouetting in the most elegant way, her dear face bright all the time with the sweetest smiles. Occasionally she had a pretty coquettish manner towards me, the memory of which is charming....

"In the last short illness her conduct, in simple truth, was angelic.

She never once complained; never became fretful; was ever considerate of others, and was thankful in the most gentle, pathetic manner for everything done for her. When so exhausted that she could hardly speak, she praised everything that was given her, and said some tea 'was beautifully good.' When I gave her some water, she said, 'I quite thank you;' and these, I believe, were the last precious words ever addressed by her dear lips to me."

Such consideration and politeness she naturally inherited. Francis Darwin says in his delightful life of his father, "He always spoke to servants with politeness, using the expression, 'Would you be so good,'

in asking for anything. In business matters he was equally courteous.

His solicitor, who had never met him, said, 'Everything I did was right, and everything was profusely thanked for.'" Of the drawings made by his children, he would say, "Michael Angelo is nothing to it!" but he always looked carefully at the work and kindly pointed out mistakes.

"He received," says his son, "many letters from foolish, unscrupulous people, and all of these received replies. He used to say that if he did not answer them, he had it on his conscience afterwards, and, no doubt, it was in great measure the courtesy with which he answered every one which produced the universal and widespread sense of his kindness of nature which was so evident on his death."

In November, 1853, Darwin received the Royal Society's Medal. He was gratified, finding it "a pleasant little stimulus. When work goes badly, and one ruminates that all is vanity, it is pleasant to have some tangible proof that others have thought something of one's labors."

November 24, 1859, when Darwin was fifty, his great work, "Origin of Species by means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life," was published. For twenty years he had been making experiments with plants and animals, and filling his note-books with facts. To his old cla.s.smate, Fox, he writes asking that the boys in his school gather lizards' eggs, as well as those of snakes.

"My object is," he says, "to see whether such eggs will float on sea-water, and whether they will keep alive thus floating for a month or two in my cellar. I am trying experiments on transportation of all organic beings that I can; and lizards are found on every island, and therefore I am very anxious to see whether their eggs stand sea-water."

Again he writes, asking Fox for ducklings and dorkings; "The chief point which I am and have been for years very curious about is to ascertain whether the _young_ of our domestic breeds differ as much from each other as do their parents, and I have no faith in anything short of actual measurement and the Rule of Three.... I have got my fan-tails and pouters in a grand cage and pigeon-house, and they are a decided amus.e.m.e.nt to me, and delight to H."

Of this book, Darwin himself says: "I worked on true Baconian principles, and without any theory--collected facts on a wholesale scale, more especially with respect to domesticated productions, by printed inquiries, by conversation with skilful breeders and gardeners, and by extensive reading. When I see the list of books of all kinds which I read and abstracted, including whole series of Journals and Transactions, I am surprised at my industry. I soon perceived that selection was the keystone of man's success in making useful races of animals and plants....

"In October, 1838, that is, fifteen months after I had begun my systematic inquiry, I happened to read 'Malthus on Population,' and, being well prepared to appreciate the struggle for existence which everywhere goes on, from long continued observation of the habits of animals and plants, it at once struck me that under these circ.u.mstances favorable variations would tend to be preserved, and unfavorable ones to be destroyed. The result of this would be the formation of new species.... But at that time I overlooked one problem of great importance.... This problem is the tendency in organic beings descended from the same stock to diverge in character as they become modified.

That they have diverged greatly is obvious from the manner in which species of all kinds can be cla.s.sed under genera, genera under families, families under sub-orders, and so forth.... The solution, as I believe, is that the modified offspring of all dominant and increasing forms tend to become adapted to many and highly diversified places in the economy of nature."

The book was written slowly, each chapter requiring at least three months. When the "Origin of Species"--which had reached its thirty-third thousand in 1888--was published, it created the most profound sensation throughout the thinking world. Heretofore, most men of science had believed that each species had been separately created by the Almighty,--that species were immutable, unchanging.

Mr. Darwin, by twenty years of study, proved to his own mind, and now to most of the world, that there has been a gradual evolution, through unnumbered ages, of one form of animal life from another. He said, "Probably all the organic beings which have ever lived on the earth have descended from some one primordial form, into which life was first breathed."

The theory of evolution was not original with Darwin. Lamarck, in 1801, published his "Organization of Living Bodies," in which he stated his belief "that nature, in all the long ages during which the world has existed, may have produced the different kinds of plants and animals by gradually enlarging one part and diminishing another to suit the wants of each." Geoffrey Saint-Hilaire, Goethe, Dr. Erasmus Darwin, the grandfather of Charles, all believed that species are descended from other species, and in various ways improved.

Some of the reasons for the belief in evolution are so simply and clearly stated by Arabella B. Buckley, in her "Short History of Natural Science," that I quote her words:--

"_All the Animals of each cla.s.s are formed on the same plan_....

"Why should the animals of one cla.s.s (such as the vertebrate or back-boned cla.s.s) be formed all on one plan, even to the most minute bones; so that the wing of a bat, the front leg of a horse, the hand of a man, and the flapper of a porpoise, are all made of the same bones, which have either grown together, or lengthened and spread apart, according to the purpose they serve? And, more curious still, why should some animals have parts which are of no use to them, but only seem to be there because other animals of the same cla.s.s also have them? Thus the whale has teeth like the other mammalia, but they never pierce through the gum; and the boa-constrictor has the beginnings of hind legs, hidden under its skin, though they never grow out. Here, again, it seems extraordinary, if a boa-constrictor and a whale were created separately, that they should be made with organs which are quite useless; while, on the other hand, if they were descended from the same ancestor, as other reptiles and mammalia who have teeth and hind legs, they might be supposed to have inherited these organs....

"_Embryos of animals alike in Structure._

"Another still more remarkable fact was that pointed out by Von Baer, that the higher animals, such as quadrupeds, before they are perfectly formed, cannot be distinguished from the embryos of other and lower animals, such as fish and reptiles. If animals were created separately, why should a dog begin like a fish, a lizard, and a bird, and have at first parts which it loses as it grows into its own peculiar form?

"_Living animals of a country agree with the fossil ones_....

"We know that certain animals are only found in particular countries; kangaroos and pouched animals, for example, in Australia, and sloths and armadillos in South America. Now, it is remarkable that all the fossil quadrupeds in Australia are also pouched animals, though they are of different kinds and larger in size than those now living; and in the same way different species of sloth and armadillos are found fossil in South America; while in the rocks of Europe fossil mammalia are found, only slightly different from those which are living there now." It seems natural to conclude that the living have descended from the fossils.

The study of the rocks has produced other "missing links" in the succession of animal life. Professor Huxley, in some lectures given in New York in 1876, described the Hesperornis, found in the western rocks,--a huge bird, five or six feet in length, with teeth like a reptile. In England a fossil reptile has been found, the Archaeopteryx, having a reptile-like tail, with a fringe of feathers on each side, and teeth, "occupying a midway place between a bird and a reptile." Flying reptiles have been found, and reptiles which walked on their hind legs.

Those who have visited Yale and Amherst Colleges must have seen the huge bird-tracks or reptile foot-prints taken from the rocks in the Connecticut valley.

Professor Huxley showed the probable descent of the horse with its hoofed foot from the extinct three-toed Hipparion of Europe, and that from the four-toed Orohippus of the Eocene formation. He declared it probable that a five-toed horse would be found, and Professor Marsh, in the West, has found the Eohippus, corresponding very nearly to Professor Huxley's description.

The question among naturalists was, "How can plants and animals have become thus changed?" Darwin showed how it was possible to effect most of these changes by "natural selection," or the choosing of the best to survive in the struggle for existence. As man by grafting secures the finest fruit, and by care in animal life the swiftest horses for speed as well as the strongest for labor, so nature selects her best for the higher development of the race.

Darwin says, "There is no exception to the rule that every organic being naturally increases at so high a rate that, if not destroyed, the earth would soon be covered by the progeny of a single pair. Even slow-breeding man has doubled in twenty-five years, and, at this rate, in less than a thousand years there would literally not be standing-room for his progeny.... The elephant is reckoned the slowest breeder of all known animals; it will be safest to a.s.sume that it begins breeding when thirty years old, and goes on breeding till ninety years old, bringing forth six young in the interval, and surviving till one hundred years old; if this be so, after a period of from 740 to 750 years, there would be nearly nineteen million elephants alive, descended from the first pair."

In various ways the weakest are destroyed. Darwin, on a piece of ground three feet long and two wide, says, "I marked all the seedlings of our native weeds as they came up, and, out of 357, no less than 295 were destroyed, chiefly by slugs and insects."

He gives this interesting instance of the struggle for existence. "I find from experiments that humble-bees are almost indispensable to the fertilization of the heart's-ease, for other bees do not visit this flower.... Humble-bees alone visit red clover, as other bees cannot reach the nectar.... Hence we may infer as highly probable that, if the whole genus of humble-bees became extinct or very rare in England, the heart's-ease and red clover would become very rare, or wholly disappear.

The number of humble-bees in any district depends in a great measure upon the number of field-mice, which destroy their combs and nests; the number of mice is largely dependent, as every one knows, on the number of cats." Hence, as Mr. Darwin shows, the frequency of certain flowers in a district may depend upon the number of cats!

Darwin showed, by most interesting experiments with pigeons, that the various breeds come from the wild rock-pigeon; that dogs are descended, probably, from the wolf; that different varieties can be produced and perpetuated under changing conditions of life; that species are only well marked and permanent varieties. He showed how organs can be changed by use or disuse; such as, the erect ears of wild animals become drooping under domestication; or moles have only rudimentary eyes, covered with skin or fur, because not needed for sight.

In the "Origin of Species," the theory of evolution received proof which was so nearly incontrovertible that the subject was brought prominently before the world as never before. Mr. Alfred Russell Wallace, an able scientist, came to the same conclusion as Darwin in regard to the power of "Natural Selection," and published, at the same time as the "Origin," an essay "On the Tendency of Varieties to depart indefinitely from the Original Type."

At once Darwin was attacked from every quarter. Probably not since Galileo showed that the earth moves round the sun has a man been so censured and persecuted for his opinions as was Darwin. He was declared atheistic, unsettling the Christian belief, and opposed to the teachings of the Bible. Professor Asa Gray of Cambridge, Ma.s.s., a devoted Christian and able scientist, defended and explained Darwin's views, now published in "Darwiniana," claiming that the doctrine of evolution is in no wise opposed to the power and goodness of the Almighty, and quotes Charles Kingsley's words: "We know of old that G.o.d was so wise that he could make all things; but behold, he is so much wiser than even that, that he can make all things make themselves." Kingsley wrote Darwin: "I have gradually learnt to see that it is just as n.o.ble a conception of Deity to believe that he created primal forms capable of self-development into all forms needful _pro tempore_ and _pro loco_, as to believe that he required a fresh act of intervention to supply the _lacunas_ which he himself had made. I question whether the former be not the loftier thought." Gray believed that "to do any work by an instrument must require, and therefore presuppose, the exertion rather of more than of less power than to do it directly." Darwin said, "There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms, most beautiful and most wonderful, have been and are being evolved." Darwin always felt grateful to Asa Gray for his defence. He wrote him: "I declare that you know my book as well as I do myself; and bring to the question new lines of ill.u.s.tration and argument, in a manner which excites my astonishment and almost my envy!... I said, in a former letter, that you were a lawyer, but I made a gross mistake; I am sure that you are a poet. No, I will tell you what you are, a hybrid, a complex cross of lawyer, poet, naturalist, and theologian!"

Darwin wisely made no reply to his critics. He said, years later: "My views have often been grossly misrepresented, bitterly opposed and ridiculed, but this has been generally done, as I believe, in good faith. On the whole, I do not doubt that my works have been over and over again greatly overpraised. I rejoice that I have avoided controversies, and this I owe to Lyell, who, many years ago, in reference to my geological works, strongly advised me never to get entangled in a controversy, as it rarely did any good, and caused a miserable loss of time and temper.