Chapter I: Part 1

Transcriber’s Notes:

Text enclosed by underscores is in italics (_italics_), and text enclosed by equal signs is in bold (=bold=).

Additional Transcriber’s Notes are at the end.

* * * * *

FROM AN EASY CHAIR

* * * * *

BY THE SAME AUTHOR

EXTINCT ANIMALS

By SIR E. RAY LANKESTER, F.R.S. With a Portrait of the Author, and 218 other Illustrations. Demy 8vo. Second Edition, Price =7s. 6d.= net.

_NATURE._--“We give the book a hearty welcome, feeling sure that its
perusal will draw many young recruits to the army of naturalists, and
many readers to its pages.”

THE KINGDOM OF MAN

By SIR E. RAY LANKESTER, F.R.S. With about 60 Illustrations. Demy 8vo. Second Edition. Price =3s. 6d.= net.

_DAILY NEWS._--“Forms one of the most stimulating and suggestive
books of recent times. We feel that we cannot praise it too highly.”

_OUTLOOK._--“This fascinating and inexpensive book ... in which much
knowledge is imparted in a manner that attracts.”

* * * * *

FROM AN EASY CHAIR

BY SIR RAY LANKESTER, K.C.B., F.R.S.

“_The world is so full of a number of things,
I am sure we should all be as happy as kings._”

R. L. STEVENSON

LONDON

ARCHIBALD CONSTABLE & CO., LTD.

1909

* * * * *

RICHARD CLAY AND SONS, LIMITED
BREAD STREET HILL, E.C., AND
BUNGAY, SUFFOLK.

_Published October, 1908._
_Reprinted January, 1909._

PREFACE

This little book is a reproduction, with some emendations, of articles which appeared in the _Daily Telegraph_ in the six months between the beginning of last October and the end of April. If it should meet with success, further collections of the same kind will be published from time to time.

E. R. L.

_August, 1908._

CONTENTS

PAGE

1. Science and the Study of Nature 1

2. The Desire to Know the World of Nature 3

3. Scares and Wonders 5

4. Work at the Pasteur Institute 9

5. The Sea Serpent 10

6. Giraffes and the Okapi 11

7. The Great Geologists of Last Century 14

8. Experiments with Precious Stones 19

9. Diamonds 23

10. Science and Fisheries 27

11. Discoveries as to Malaria 29

12. Malta Fever 34

13. A Cure for Sleeping Sickness 36

14. Tsetse-Flies and Disease 38

15. Monkeys and Fleas 41

16. The Jigger Flea 42

17. Public Estimate of the Value of Science 43

18. The Common House-fly and Others 45

19. Cerebral Inhibition 48

20. Colour-photography and Photographs of Mars 49

21. Origin of Names by Errors in Copying 50

22. False News as to Extinct Monsters 51

23. Mistletoe and Holly 52

24. The Cattle Show 55

25. The Experimental Method 59

26. Hypnotism and an Experiment on the Influence
of the Magnet 60

27. Luminous Owls and Other Luminous Animals
and Plants 65

28. Reminiscences of Lord Kelvin 68

29. The So-called Jargon of Science 70

30. Rats and the Plague 73

31. Ancient Temples and Astronomy 78

32. Alchemists of To-day and Yesterday 84

33. A Story of Sham Diamonds and Pearls 88

34. The Nature of Pearls 89

35. A King Who was a Zoologist 93

36. The Transmission to Offspring of Acquired
Qualities 97

37. Variation and Selection Among Living Things 103

38. The Movement, Growth, and Dwindling of Glaciers 108

39. Votes for Women 117

40. Tobacco and the History of Smoking 124

41. Cruelty, Pain, and Knowledge 131

* * * * *

FROM AN EASY CHAIR

1. _Science and the Study of Nature_

This volume consists of brief notes in plain language on a variety of scientific matters. I speak of new discoveries, real or so-called by mistake; of old well-established facts and explanations of strange occurrences which are more familiar to men of science than to people who have not had the time and opportunity to ascertain what is, and what is not proved and known about Nature and her ways. I do not address my reader from the professor’s chair, but from an easy chair. Just as in the club or my friend’s smoking-room, I might talk of these things, so do I propose to talk here. My hope is that what I have to say will interest those who are not experts in science, and yet have a desire for trustworthy information and opinion on the vast variety of topics which come up day by day for consideration and discussion, and can only be explained or rightly understood by the aid of that systematised knowledge which is called science.

* * * * *

Science and the scientific point of view have a very wide, indeed, an unlimited range. Though the making of discoveries of real importance and the full understanding of the steps by which they are made involves, as a rule, long study and special training, yet there is a vast deal of healthy excitement and pleasure connected with the progress of science, in which all can share by receiving, as it were, messages from the front. By contributing true records and observations of fact which serve, in however small a way, as ammunition and material of war for the use of the fighting line, we can all help and take part in the advance of science.

A great feature of what is called science is that it is true. The actual result achieved by science is the record of “that which is”--it can be examined, tested, and proved. But science does not merely collect accurate records of fact. In order to discover new things, new relations, and hidden causes she has to make use of guesses and flights of imagination. The “hypotheses” or guesses are not wild ones, but reasonable suppositions based on careful consideration of existing knowledge. They are never mistaken by trained workers in science for “facts,” nor put forward as such. On the contrary, they are tested and so confirmed or rejected by experiment or trial. Hence the necessity of accuracy in observation for the purposes of science; hence the proverbial “scientific accuracy.” It is of no use to form a guess based upon erroneous statements. It is mere waste of time to accept and build theories upon loose wonder-mongers’ gossip. And, further, the evidence which you obtain in order to confirm or dismiss your “guess” must be equally beyond suspicion as to its accuracy. It must be an observation of fact free from prejudice and illusion.

Your guess, if proved to be true, adds to the solid record of science new facts and new proofs of relationships, which again lead on the imagination of men of science to new guesses, and so to new confirmation or rejection, and to the growth of the vast record of accurate knowledge. To seek out in the endless whirling complexity of things which surround us in earth, sky, and sea, the truth, the knowledge of “that which is,” of the relation of these things to one another as cause and effect and their action and influence on ourselves--this is the aim of science. To substitute real understanding and the power of control of the surrounding world for the misleading and cruelly harmful conceptions existing in the minds of simple unskilled mankind--this is the daily achievement of science.

2. _The Desire to Know the World of Nature_

The practical value of science in securing the happiness of human communities is not, however, the reason which operates most strongly in exciting men and women to give themselves to the cultivation and improvement of this or that branch of it. A rich banker one day was looking round the Natural History Museum with me. It was his first visit. After a time he said, “It’s very fine! wonderful! But what’s it all for? Where does the money come in? That’s what I can’t understand. Why does the Government spend money on this if it don’t lead to making money?” I tried to convince him that there exists in us all a divine “curiosity,” a desire to know regardless of profit or loss, a thirst which we may cultivate and satisfy, in the full assurance that whilst its satisfaction is a delight in itself, we are all the while fulfilling the destiny of man, helping in the conquest of Nature. My friend had apparently lost that instinctive thirst which is the primary impulse to the pursuit of science, that capacity for pleasure which Robert Louis Stevenson truly notes in the words of the child of his “Garland of Verse”:

“The world is so full of a number of things,
I am sure we should all be as happy as kings!”

The existence of that little child and of numberless “grown-ups” who have become or have never ceased to be, in this matter, even as he, is the reason why science has its helpers and workers of all ranks, and it is of them that I chiefly think in writing these notes.

At a dinner of the Savage Club a year or so ago my friend Dr. Nansen, the Norwegian Minister, quoted some lines from a Scandinavian poet, which he translated somewhat as follows: “As you journey through life do not go too fast, do not press on blindly; there are so many beautiful things by the way. Turn your head, stay a few minutes. Leave the dusty road. Take in and enjoy the wonders and delights which are at your feet.” Motorists, please take note!

For those who can enter more thoroughly into the pursuit of science there are even greater joys. To the very few there is the privilege not merely of realising well-established truths, and of perhaps assisting in securing their foundations or extending their application, but of discovering vast unexplored regions, new possibilities, new revelations of the unfathomed depths of Nature’s workings. Though few can hope to be leaders in these enthralling adventures, yet we can be close to those who are, and, holding their hands, sympathise with their soul’s vision.

“Then felt I like some watcher from the skies,
Or the stout Cortes, when, with eagle eyes,
He stared at the Pacific....
Silent, upon a peak in Darien.”

Such a one need have none of the conventional setting of romantic enterprise. He may be standing before a much-stained table, covered with bottles, in an atmosphere of acrid fumes, with a test-tube in his hand, or he may be just raising his head with a far-off gaze, as he sits, bent o’er a microscope, in London.

3. _Scares and Wonders_

There are certain subjects which come within my ken upon which paragraphs are published in the papers nearly every other day of a wildly romantic and misleading character. These subjects may be classified as: (1) Living and extinct monsters. (2) Cures for cancer and tubercle. (3) Unsuspected dangers of infection by disease-germs. It would hardly be pleasant for me to quote these paragraphs in order to deny their statements. They are often headed, “For the Little Ones,” or “From a Foreign Correspondent.” The old-established and better title for such announcements is “For the Marines.” I shall endeavour to mention as they occur to me, among other things, new and duly-certified facts relating to monsters, and to the investigation of disease. With reference to reports which have been seriously put forward during the past year, I may say that the alleged discovery of a mammoth in North America 71ft. long and 40ft. tall is nonsense. In the announcement to which I allude, the measurements have been altered from some original and more correct statement and made to appear astonishing by error or design.

No new facts of importance bearing upon the treatment of either cancer or tubercle have been lately discovered which can be explained to the general public. Work is proceeding nevertheless. No new source of danger from disease-germs has been detected since this time last year. It is true that the dust in railway carriages, and especially in sleeping-cars, which are not properly cleaned every day after occupation by travellers, is full of microbes, and, like the dust of rooms which have been crowded by human beings, may be a source of disease infection. The remedy for this is careful cleansing after each journey, and a special construction of the cars like a tiled bath-room, so as to avoid the accumulation of dirt. At present this is, and long has been, neglected.

Another serious and more recent danger is that arising from the crowding of passengers in underground railway tubes. Both in Paris and London this has been recognised as a real and pressing danger. Trouble has been given by the dust raised in the Paris Tube, but the danger caused by dust has been avoided in London. It is a definitely-ascertained fact that many bacteria, including disease-producing kinds, are rapidly killed by exposure to strong sunlight. Hence underground tubes and the chinks and recesses of railway carriages are more liable to harbour disease-germs than the open-air roadways and the carriages which ply on them. Great cleanliness and the use of germicide washing fluids are the obvious precautions to be taken in the absence of sunlight.

As to mammoths and elephants--the former is a misspelling of the word “mammont,” the name given by the natives of Northern Siberia to the extinct elephant, hairy, but otherwise closely similar to the Indian elephant, which within the period of prehistoric man (50,000 to 150,000 years) was abundant over the whole of the northern part of the Northern Hemisphere. Mammoths’ tusks (ivory) are still largely imported from Siberia. The biggest African elephant may, perhaps, stand 13ft. at the shoulder. No mammoth or other extinct elephant seems to have exceeded this. The stuffed African elephant in Cromwell road measures 11ft. 2in. at the shoulder. Mr. Carnegie’s great extinct reptile Diplodocus is only 12ft. 9in. from the ground at the highest part of its back. The biggest tusk of a recent elephant ever seen was bought by me for the Natural History Museum seven years ago. It weighs 228lb., and measures 10ft. 2in. along the curve. It was recognised three years ago by Mr. Jephson (one of Stanley’s companions) as one of a pair which he had weighed in Central Africa. It was in the possession of Emin Pasha when that unfortunate gentleman was “rescued” by Stanley and Jephson. After the subsequent assassination of Emin, his ivory treasure found its way to Zanzibar, and this tusk being part of it, was sold and brought to London.

A real new monster of great size is the carnivorous reptile described by Professor Osborne, of New York, as Tyrannosaurus. There is no mistake or exaggeration about this report. The specimen is in the New York Museum, and has been described in detail and drawn to scale by Professor Osborne. The skeleton stands up like that of a huge bird or a kangaroo on the two hind legs--as does that of the vegetarian reptile Iguanodon. The Iguanodon and the Tyrannosaurus are of about the same height, namely 17ft. But the new monster has enormous tiger-like teeth, twelve on each side of the jaw, above and below, and the jaws are three feet long, whilst the whole head is broad and short. Iguanodon, on the other hand, has been long known from English and Belgian rocks, and can be seen in Cromwell Road. It has a beak like a tortoise, and the small teeth of a vegetable-feeder. Both animals had very short front limbs or arms, but in Tyrannosaurus these are really ridiculously out of proportion, according to more familiar standards, for the whole arm is not bigger than one of the toes of the hind foot. This new giant carnivorous reptile is found in rocks of the same age as our greensand and chalk in Wyoming, U.S.A. It preyed upon huge vegetable-eating reptiles, the remains of which are found in the same strata, and have been reconstructed.

The mere size of these extinct reptiles is a very natural cause of wonder and admiration. At the same time, it is well to remember that the body of the largest African elephant is as big, or very nearly as big, as the body of the biggest of these extinct reptiles. Some of these giant extinct reptiles had very long tails and necks, which the elephant cannot boast. No extinct animal is known which approaches in bulk the great whales of various kinds at present inhabiting the sea. The striking thing about many huge extinct animals is that they are represented to-day by similarly constructed animals of much smaller size. Thus we know giant extinct sloths, which contrast strangely with the small living sloths of to-day, giant extinct rat-like animals and giant extinct kangaroos far exceeding the bulk of living rats and kangaroos. But it is distinctly not true that all recent animals are degenerate and small as compared with extinct related kinds. The modern horse is far larger than its extinct ancestors, which we can trace back in a gradual diminishing series to a little beast no bigger than a spaniel. So, too, the earliest elephants known are quite small creatures.

The interesting point about extinct animals is really not so much that they were often large of their kind, but that they are often of kinds quite unknown at the present day among living animals. On the other hand sometimes (but by no means always) they can be shown to be connected as ancestors to living animals by a series of intermediate forms. The remains of the connecting forms are found embedded in successive rock-strata, intermediate in age between the present day and the remote period when the earliest members of the series were alive and flourishing--and we can follow out in many instances (for example, in the pedigree of the horse, and again of the elephant) the gradual but very extensive changes by which the descendants of a long extinct kind of animal have been “transformed” into modern recent animals, familiar to us.

4. _Work at the Pasteur Institute_

Professor Elias Metschnikoff was busy, when I saw him at the Institut Pasteur in Paris last September, with an experimental investigation of “appendicitis.” He finds that chimpanzees can exhibit this disease, and he is led by experiments on those animals to believe that a gas-producing micro-organism--the bacillus aërogenicus--already known as occurring in the human intestine--is especially active in exciting the disease. Parasitic worms or other foreign bodies must first wound the delicate lining of the appendix before the virulent gas-forming bacillus can penetrate and start inflammation and abscess. Metschnikoff was also investigating a disease of tropical regions, known as “the Yaws.” Most people would imagine that this name refers to a disease like the gapes, but it is quite different, being an ulceration of the skin caused by a spirillum.

Spirilla--corkscrew-like threads of excessive minuteness--are parasitic organisms, like bacteria, bacilli, and micrococci. They are of different kinds--some harmless, some deadly. One is common in the mouth of the healthiest of us--another causes one of our most terrible diseases. They can be distinguished by the microscope, though much alike. What microscopists call “dark-ground illumination”--that is, illumination by horizontal rays of light, obtained by a prism attached below the glass slip on which the object is placed for examination with the microscope, has been found at the Institut Pasteur to be a very ready way of showing the spirilla in fresh blood or sputum. The spirilla are alive, and are seen when highly magnified, shooting rapidly across the field of view with a corkscrew action, like brilliant silver threads. The detection of the microbe which causes an infective disease, is often the first step to the control of the disease, or to knowledge which enables man to avoid the disease altogether. Some striking examples of this have occurred of late years.

5. _The Sea Serpent_

The sea-serpent rarely puts in an appearance now, though a Cornish “manifestation” was reported last year. A recent account of a strange marine monster, declared by some to be, of course, the sea-serpent, seen but to disappear, was that given by Lord Crawford’s companions two years ago. In that case, and in others in which a huge fin-like structure, supported by fin-rays, has been seen projecting from the mysterious animal, it is not improbable that what was seen was a large seal of the “eared” kind, raising one of its long, webbed hind-feet from the water, a trick which some of them are known to have. Other reputed sea-serpents have been, in reality, a school of porpoises, or a line-like flight of sea-birds, or a mass of seaweed, or a whale in association with one or other of these--or, again, a real marine snake 5ft. long (such are well known and very poisonous), or a ribbon-fish 12ft. long. There is “no reason why there should not be” a huge and seldom-seen kind of animal living in the sea--like a serpent in appearance. No one can say, as the result of observation, that there is not, since no one has thoroughly explored the dark, unfathomed depths of ocean. Yet we gain very little when we have admitted our ignorance, and agreed that there is no reason why something should not be. The real question is, “Does the thing in question exist?” not “Could it possibly exist?” Does the great sea-serpent exist? The answer to that is, There is not much evidence to show that it does. Most persons who have looked into the matter would be willing to bet 100,000 to 1 against its being captured, dead or alive, and brought before the Royal Society within ten years’ time. Unless it be so captured and “tabled” it matters very little whether it exists or not. It must be “discovered” in order to become really interesting.

6. _Giraffes and the Okapi_

The baby giraffe at the gardens in the Regent’s Park is a most interesting and beautiful creature. In that respect she only resembles on a small scale her grown-up relatives. Next to elephants, giraffes take precedence for strangeness, beauty, and imposing size. Certainly they have done so with me ever since I turned one Sunday afternoon long ago from the great novelty of the day, the first hippopotamus sent from Egypt, round whom the world of fashion was crowding, and gazed into the beautiful eyes that hung over me, supported by a gracefully-curving neck. My tender regard for the beautiful creature was not shaken even when I felt a sudden jerk to the elastic band passing under my chin and saw my new Leghorn straw hat, with its ornamental bunch of Egyptian wheat and broad pink ribbon, disappear between the lips of the beauty. A slow right and left movement of the jaw followed, accompanied by a tranquil kindly look suggestive of a desire for more. That was one of the old stock of Regent’s Park giraffes, who bred freely at the gardens and made money for the society. They died out thirty years ago or more. From time to time since then there have been one or two mis-shapen giraffes in London, but they did not eat children’s hats nor produce young of their own. A new dynasty of Kordofan giraffes has now arrived, and a better spirit prevails.

The most interesting thing about the giraffe is the okapi. The remark sounds absurd, but it is true. The okapi is the new animal from the Congo forest of Central Africa, discovered in 1901 by Sir Harry Johnston. It is as big as a very large stag, has a neck like a deer, and is striped on the haunches and legs, not spotted as is the giraffe. Yet its teeth and its horns prove it to be a close ally, not of deer, but of the giraffe. Any points of agreement between giraffes and the okapi are, therefore, important. I have examined the baby giraffe at the Zoo, and find that she has stripe-like bands of hair on the face and on other parts of the head. Both her father and mother are from Kordofan, and have some six or seven strongly-marked bands of dark hair over the eyes and on the muzzle. It is important to note any colour-striping in the giraffe’s skin, since the giraffe’s colour-markings are mostly in the form of great spots, whilst the okapi is only marked by stripes or bands something like those of a zebra, but confined to the haunches and the legs, the rest of the body being dark brown. The tendency to develop colour stripes in the giraffe is important, since it shows us that the stripes do not separate the okapi absolutely from the camelopard; they are a common possession or possibility of the two animals. It was my examination of a half-brother of the little giraffe now alive at the Gardens which led to the discovery of striping on the head and face of giraffes. The mother in that case had died before the birth of her young one, and the dead calf was given to me by the secretary of the Zoological Society. Sixty-eight years ago Sir Richard (then Professor) Owen received a new-born giraffe from the Gardens, and reported on it to the Zoological Society. No one had examined one since that date; none were obtainable from the Zoo, and I could get none from African travellers and sportsmen, in spite of urgent requests. I was accordingly greatly pleased to secure one from the London Gardens. A great peculiarity of the young giraffe is that it is born with a pair of well-grown horns, nearly an inch long, and covered with coarse black hair. No other horn-bearing mammal--no antelope, buffalo, ox, sheep, goat, stag, or other deer--is born with horns, so far as we know, and we know a good many of these animals well. Before birth the young giraffe’s horns are flat from back to front, and quite soft and flexible. They can be pressed backwards, so as to be made to lie flat on the head. Directly after birth a hard, bony deposit commences inside the horn, and after some years’ growth it becomes firmly fused to the skull. But the hard bony core never breaks through the hairy skin which covers it. The bony core of the okapi’s pair of horns, on the contrary, does “cut” or break through the skin, exposing a sharp, hard point, a quarter of an inch in length. In the deer tribe, as everyone knows, the point of the bony horn-core spreads out as a large, branching growth from which all covering is shed, and forms the “antler.” The deer tribe shed the antlers every year from the top of the horn-core, and grow a new and larger pair to take the place of the old ones. Moreover, in them the horn-core itself is a stem-like upgrowth of the bone of the skull (of the frontal bone). In the okapi and the giraffe the horn-core is a separate bone, free at first and fusing with the skull only when the adult condition is reached. The little antlers or bare-points of the okapi’s horn-cones or cores seem to be shed in segments as growth goes on, and are only minute things compared with the antlers of stags. The giraffe’s horns, on the other hand, always remain covered by skin and hair and have a broad, rounded top, not a sharp point.

The real clinching feature in the okapi and giraffe which decides at once their close affinity to one another is found in the outer tooth on each side of the group of eight teeth placed in the front of the lower jaw. In both this particular tooth has a broad, chisel-like crown, divided into two portions by a deep vertical slit. None of the other ungulate or hoofed animals have this very curious shape of tooth. It is a sort of family “mark” or “feature” in okapis and giraffes, as may be seen in specimens shown in the gallery of the Natural History Museum, where we have now no less than three fine, well-stuffed okapis and several varieties of giraffe.

7. _The Great Geologists of Last Century_

The centenary of the foundation of the Geological Society of London, celebrated last year, was a genuine festival in the scientific world. Though geology had its teachers and searchers before 1807 (Hutton and Werner, and the Neptunian and Plutonic schools, with their theories as to the origin of rocks on the one hand by marine deposit, or on the other by igneous agency, flourished before that date), yet it is true that the adequate conception of the problems of geology and the proper use of accurate observations and of judicious theory based on those observations, in relation to the problems of geology, coincided with the foundation of the society. It was not the first “special” scientific society founded in London; there was already the Linnean Society (founded in 1788) for the cultivation of zoology and botany. Yet it incurred the displeasure of the worthy president of the Royal Society, Sir Joseph Banks, who at first joined it, and then withdrew from it, when, in 1809, it ceased to be a dining-club, meeting at a London tavern, and acquired rooms of its own at No. 4, Garden-court, Temple. Apparently there was a notion in those days that the “Royal Society for the promotion of Natural Knowledge,” founded in 1662, should exercise a sort of paternal control over any society formed for the special promotion of one branch of science. Independence has, however, been found to be the healthiest condition, and we now have not only the Linnean and the Geological, but the Zoological, the Chemical, and the Physical Societies, vigorous and important corporations, publishing their “Transactions,” and meeting for discussion. There is, it is true, a danger that the Royal Society may be left eventually, owing to these independent establishments, in the sole possession and control of the doctors and the engineers. It is a curious fact that the word “physiology,” which in Cicero’s time (he says “Physiologia naturæ ratio”) and in the Middle Ages meant what we now call “natural history,” has been abandoned by other sciences, and appropriated by the medical men. In England, but not abroad, the doctors have even usurped the words “physician” and “physic.” In France, on the contrary, and more correctly, Lord Rayleigh and Sir William Crooks are called distinguished “physicians,” and the theory of the luminiferous ether is “physic.”

The Geological Society issued its first volume of Transactions in 1811. The origin of the society is there stated to be due to “the desire of its founders to communicate to each other the results of their observations, and to examine how far the opinions maintained by the writers on geology are in conformity with the facts presented by nature.” A more exact and intelligible statement of the attitude of scientific men, then and now, could not be formulated.

There are few, if any, among us now who knew many of the original members of the Geological Society, but I remember meeting, when I was a youth, Leonard Horner, the first secretary of the society, and father-in-law of Sir Charles Lyell. I also knew Dr. Peter Mark Roget, an original member, who was the oldest fellow of the Royal Society when he died in 1869. Sir Henry Holland, the father of the present Lord Knutsford, became a member in 1809, and published a paper on the rock-salt district in the first volume. He was an eminent medical man, and a great traveller. He wrote, amongst other things, upon the turquoise mines of Persia and upon longevity. He was a friend of my father’s, and I had the advantage of talking the latter subject over with him before I wrote a little book on “Comparative Longevity” in 1869.

It was not until 1825 that the Geological Society obtained a charter, and was incorporated. Two great names appear in the first council of the newly-incorporated society--Murchison and Lyell. Murchison became the Director of the Geological Survey, and as “Sir Roderick” was a familiar and picturesque figure in the scientific world of the second and third quarters of last century. He wore an Inverness cape and a tall hat with a large and much-curled brim, an old-fashioned stock, and a tail-coat. In his hand he always grasped a large, handsome cane, with which he expressed his applause during the discussions at the society, or emphasised his own remarks. He was fond of alluding to himself as “an old soldier of the hammer,” and almost always entered into a discussion with these words, “It is now, sir, a quarter of a century since, in company with my illustrious friend, Sir Somebody Something, I had the privilege and pleasure of showing that”--whatever it might be. Discussions at the Geological in the sixties and seventies were real, animated, almost violent discussions. I need hardly say that they were perfectly delightful. Godwin Austen was a fine, incisive speaker, who seemed ready to back his statements and views with his fists, if need be. Lyell, the greatest of all, was most modest, and almost timid in pressing an opinion, but full of personal experience and minute knowledge of facts. John Phillips, the nephew of the father of English geology, William Smith, was mellifluous and persuasive; Jukes, robust and defiant; Huxley (secretary and then president), clear, trenchant, and uncompromising. I remember an occasion when Sir Roderick, with tears in his voice, if not in his eyes, declared he would not stay in the room to hear that fossil fishes were discovered in his own special domain--the Silurian rocks, where he had long since shown that they did not occur--and he left the meeting. Many Silurian fishes have now been found, but we all loved Sir Roderick for the heart and feeling which he threw into his work and his public utterances.

The aim of geology is to describe accurately the long succession of changes in the crust of “this cooling cinder,” the earth, and to assign them in an orderly way to their causes. Hence, it calls upon nearly all other branches of science for help--astronomy, physics, chemistry, mineralogy, botany, and zoology. At the same time, it is essentially a recreative pursuit, for, as Mr. Horace Woodward says in his _History of the Geological Society of London_--published by the society--“the fulness of the science can never be attained without the vivifying influence of mountain and moor, of valley and sea coast.” It is owing to this that the soldiers of the hammer, from Murchison, Sedgwick, Lyell, Ramsay, Etheridge, Salter, onwards to the present generation of “stone-crackers,” are amongst the happiest, most genial, and mentally alert of our men of science.

That word “stone-cracker” I take from a letter addressed to me when I was a boy of twelve by the Rev. J. S. Henslow, Professor of Mineralogy and later of Botany at Cambridge, founder, with Adam Sedgwick, the great Woodwardian Professor of Geology, of the now flourishing Cambridge Philosophical Society, and the teacher, guide, and fateful friend of Charles Darwin. It was he who sent Darwin on the voyage of the _Beagle_. I had met this wonderful old naturalist at Felixstowe when exploring the marshes for rare plants and insects with my father. My father was a first-rate man at a country walk, and could tell you all the time about the flowers, flies, stones, and bones you might encounter. But Henslow surpassed him. I remember to this day nearly every word Henslow said, and everything he did on that memorable afternoon nearly fifty years ago. Amongst other things he explained how the rough flint implements recently discovered in river gravels--proving man’s great antiquity--could be shown to owe their shape to blows, each blow causing a “conchoidal” fracture. And he struck with his hammer some very large flints which were lying in a heap in the meadow, and produced the most perfect dome-like broken surface or bulb of percussion. He promised to give me a real palæolithic flint implement and also a geological hammer. The letter which reached me later in London ran as follows: “Dear incipient Stonecracker--Enclosed you will find a draft for 10_s._ with which, at the shop in Newgate-street, you can obtain a geological hammer identical in all respects with my own.... In a separate parcel I send you a flint implement which I obtained myself in the gravel pit at St. Acheuil....” The hammer, the flint-axe, and the letter are to this day treasured with deep affection and reverence for the giver, by the boy who was thus so kindly initiated in the “art and mystery” of Stone-crackers. Henslow died in 1861 at the age of 65. His daughter was the first wife of Sir Joseph Hooker, the great botanist and traveller, who celebrated his ninetieth birthday in July, 1907, and is still in full mental and bodily health and vigour.

8. _Experiments with Precious Stones_

A man of science cannot say a word about experiments with precious stones nowadays, but he is liable to be misunderstood and represented as having discovered how to make valuable gems out of dirt, or of enormous size, and in vast quantity. Last year the production of a few small crystals by the electrical decomposition of bisulphide of carbon was announced as something to affect the stock market instead of as a matter of interest to a few learned chemists. The crystals were supposed--erroneously as it turned out--to be diamond. We were also gravely told that a competent French chemist had discovered, and that the distinguished geologist, Professor Lapparent, had communicated the fact to the Academy of Sciences, that the radiation of radium acting on “corindon,” or, as we should prefer to write it in England, “corundum”--a base, dull, colourless crystal--converts that dull substance into sapphires, rubies, emeralds, and topazes--and that the dealers attest the value of the precious stones so produced. This is really great nonsense, and arises from a little confusion in the use of the names of precious stones, and ignorance of what the substances indicated by those names are--defects which we cannot attribute to the French chemist, but must suppose to have “crept in” to the reports which crossed the Channel. Corundum is a colourless crystal, opaque or translucent. In chemical composition it is the oxide of aluminium--standing in the same relation to that light, white metal as rust or hematite ore does to the metal iron. It would not be at all astounding if by simple treatment we could convert corundum into sapphire or into ruby, since sapphire and ruby have precisely the same chemical constitution as corundum--are, in fact, only coloured varieties of corundum. Sapphire is blue, transparent corundum; green and yellow “sapphires” are also common. The Oriental ruby is similarly only red, transparent corundum--like it only oxide of aluminium or alumina.

Diamonds are pure crystalline transparent carbon. Commonly they are colourless and transparent, but are sometimes black or white and opaque. Transparent diamonds are often found of a straw colour, rarely of a deep blue (the Hope Diamond), more rarely green (the Dresden Diamond), and rarest of all red.

If radium were really able (as some people have wrongly inferred from the French experiments) to change the chemical nature of corundum and convert it into topaz and emerald, the case would be very different from that of merely changing the colour of the corundum. What is to-day called “topaz” is a sherry-yellow crystal consisting of silicate of alumina and of fluoride of alumina. It turns pink when heated, and is also known of a blue colour and colourless. The topaz of the ancients from the coasts of the Red Sea is of a different chemical nature, and is now called peridot. Yellow corundum is sometimes wrongly called Oriental topaz, and the yellow-brown quartz crystals properly known as cairngorms are sometimes wrongly called Scotch topaz. So that the word “topaz” is used loosely as well as strictly, and confusion results. Emerald is widely distinct from corundum, sapphire, and ruby. It is a silicate of alumina and beryllium, and in its coarse and pale-coloured variety is known as beryl.

From all this it appears that some names of precious stones indicate substances quite distinct from one another chemically, built of differing elements, and also _per contra_ that what is actually one and the same kind of precious stone in chemical composition and native crystalline form may present examples possessing various colours and degrees of transparency, each variety being called by a distinct name, and regarded popularly as a distinct kind of stone. Radium rays can convert colourless alumina or corundum into blue alumina (sapphire) or red alumina (ruby), but they cannot change alumina into beryllia (that is into emerald), nor into fluoride (that is into topaz).

One naturally asks, “To what is the colour of these precious stones due?” The answer is difficult, because very minute traces of chemical impurity, such as iron, cobalt, manganese, or chromium may suffice to tint an otherwise transparent, colourless crystal with the brightest red, yellow, blue, violet, or green. Moreover, it is certain from what we know of traces of metallic impurity in artificial glass that it may exist in such a state of chemical combination as to give no tint whatever to the glass, but after prolonged exposure to light or other agencies, the minute impurity may combine chemically with oxygen present in the glass and develop colour. Thus, for instance, old window-glass often assumes a violet or amethystine tint after long exposure. This varying colour of the combinations of metals according to whether they are oxidised or not, and the degree of oxidation, or the special salt which they may form, is in itself an unexpected thing to those who are not chemists. The metal chromium, for instance, gives rise to colourless, to yellow, red, green, and blue combinations. Manganese, a metal commonly associated with iron, gives rise to brilliant green, to violet, and to wine-red combinations, and if scattered as microscopic particles of black oxide in glass would produce no colour effect at all. From what we know of glass and the ease with which it is coloured to every shade of the rainbow by the admixture of traces of metallic impurities--so that “paste” or glass gems of all colours can be manufactured--it is not surprising to find that natural crystals, transparent and often devoid of colour (such as corundum, diamond, quartz, and topaz), are yet also found more or less frequently coloured in various tints. Nevertheless, it is the fact that in very few cases have chemists been able to prove by analysis what precisely is the cause of the colour in any given crystal or precious stone, although they may strongly suspect this or that as the colour-giving impurity. The actual quantity of a metallic impurity sufficient to give a tint is so excessively minute that the chemist finds it impossible to determine what it is by examining one small precious stone. He has not a sufficient bulk of material to operate on.

Having reached this point, we can see that such potent disturbing agents as the rays of radium--penetrating a colourless, or faintly-coloured, crystal--may determine oxidation or other chemical combination within the crystal of traces of metal (iron, cobalt, manganese, chromium) already present there, and so give it an increased colour or an altogether new tint. In 1905 (therefore long before the recent French experiments had shown that the radium rays will act in this way on corundum, the “base variety” of sapphire and ruby), Sir William Crookes published an account of his experiments as to the action of the radium rays on the diamond. “Some fine colourless crystals of diamond,” writes Sir William Crookes in 1905, “were embedded in radium bromide, and kept undisturbed for more than twelve months. At the end of that time they were examined. The radium had caused them to assume a beautiful bluish-green colour, and their value as ‘fancy stones’ had been materially increased.” On another occasion Sir William found that a yellowish “off colour” diamond had its tint changed to a pale blue-green when embedded for six weeks in a tube with radium bromide. (I have seen this stone.) He also has succeeded in improving the clearness of diamonds by exposing them to radium rays. Everyone who has experimented with radium knows that it causes the glass which may be used to keep it covered to develop a brown or purple tint. This, then, is the explanation of the results obtained by the French observer with corundum, as reported a few months ago. There was no “transformation” of one substance into another, nor did he himself suggest that there was. The radium rays merely acted chemically on minute impurities present in colourless or pale-coloured crystals, and so produced colour as they do in diamonds or in glass.

9. _Diamonds_

His Majesty King Edward was presented with the great Cullinan diamond from the Transvaal in November 1907. This diamond weighs one pound and one-third (avoirdupois)--more than 21 oz. I have placed a good glass model of it in the Central Hall of the Natural History Museum; in the case with it is a glass model of another big diamond, the “Excelsior,” as now cut, and also models of the “Pitt” diamond, in the rough and in the cut condition. Diamonds lose enormously in the process of cutting. The Excelsior, like the Cullinan, is a Cape diamond of fine quality, and free from colour. It was the biggest diamond known until the giant Cullinan was found: in the rough it weighed 7 oz., or less than a third of the Cullinan. As now cut, it only weighs 1-3/4 oz. It is reduced to a quarter of its original size.

In the same way, the Pitt diamond, an Indian one, named after General Pitt, of Madras, weighed originally 3 oz., and is now (it is in Paris, in the Louvre, and is called “The Regent”) less than an ounce in weight. The biggest Indian diamond known--the Nizam--is not quite twice this size, whilst the Kohinoor, which is probably a fragment (a third) of the “Great Mogul”--a diamond which has disappeared, leaving only tradition and surmises as to its history--weighs no more than three-quarters of an ounce. This seems a small affair by the side of the twenty-one ounces of the Cullinan.

No one can guess what will happen to the Cullinan in cutting it. At the best, it may be reduced to something between four and five ounces in weight, and it may “fly” into fragments. It would be necessary deliberately to cut it up into smaller stones in order to obtain the full result of flashing of light and colour which twenty-one ounces of diamond can produce. And the operation of cutting and polishing is enormously expensive. One would have hoped that Sir William Crookes and other men of science would have been asked to examine this wonderful mass of transparent carbon by means of polarised light, Röntgen rays, and radium, and to determine exactly its specific gravity before it was broken up. Indeed, it would probably have retained its greatest interest and value if never cut at all.

Glass or “paste,” as it is called, is made which cannot when new be distinguished from diamond by anyone but an expert, armed with the necessary tests. And the same is true as to paste imitations of all precious stones excepting the emerald (whose beautiful green tint cannot be exactly obtained), the cat’s-eye, which has a peculiar fibrous structure, and the opal. The real value and quality of precious stones, as compared with glass, depends on their durability, their hardness, their resistance to scratching, and “dulling” of face and edge. Even our Anglo-Saxon ancestors, as may be seen in the fine collection recently dug up at Ipswich by Miss Layard, and placed in the old house serving as the municipal museum there, made gems of glass and paste. In modern times the art of making artificial “precious stones” has reached a degree of perfection which, so far as decorative purposes are concerned, leaves the natural stones no claim to superiority.

Gigantic as the Cullinan diamond is, it represents only about half the daily output of the De Beers mines. By the end of 1904 ten tons of diamonds, valued at £60,000,000 sterling, had been removed from the Kimberley mines. It is difficult to imagine what has become of them all, and since they are, unlike paste, durable and permanent, how the demand for additions to those in use, keeps up. Twelve years ago about four million pounds was spent annually by the public on the purchase of diamonds. It is stated that the annual demand and expenditure are now even larger.

Diamond is a peculiar form or variety of the chemical element carbon--a very peculiar form most people will say who remember that charcoal and lamp-black are the common form of carbon. That one and the same unchangeable chemical element can exist as an amorphous black lump or powder, and also without addition or loss of chemical constituents, as the clearest, hardest, and most brilliant of crystals, is a paradox. The same strange capacity for existing in two totally different forms is exhibited by other fairly familiar elements. Sulphur is found in tertiary water-deposited clays in Sicily (it has nothing to do with Etna or Vesuvius) in the form of clear, lemon-coloured crystals half an inch or more in length. If you take some commercial stick-sulphur and melt it in a porcelain spoon, and pour half the melted stuff like treacle into a jar of water, you will find that it cools as translucent threads which are pliable and soft. The other half which you leave in the spoon to cool shoots out into the form of long brittle crystals of a needle-like shape. These two varieties of sulphur are nearly as different as lamp-black and diamond.

Diamonds are found at the Cape in a “blue ground” which is of volcanic origin, formed by the action of steam under enormous pressure. The blue volcanic mud has been thrust up from great depths in the earth’s surface in the form of “pipes” 100 yards to half a mile in diameter. It has long been known that at very high temperatures (4,000 deg. Centigrade) the metal iron dissolves carbon. The late Professor Moissan, of Paris, obtained artificial diamonds by suddenly cooling the iron in which carbon was dissolved by plunging the crucible into water. The outer shell of iron cools and forms a tightly closed shell enclosing the still liquid core. As this core cools it tends to expand, and thus produces an enormous pressure. The melted carbon cooling under this pressure assumes the crystalline colourless form known as diamond. There is good reason to believe that diamonds are formed, or have been formed, in association with metallic iron in a similar way, on a large scale, in great depths of the earth’s crust, and are shot up to the surface with other débris in the volcanic steam mud which is the “blue ground.”

A few diamonds of small size have been found in the Ural Mountains, otherwise they are not natural products of the northern hemisphere. It is in India, Australia, South America, and South Africa that they are picked up, either in beds of streams, or in peculiar volcanic mud, or embedded in even harder rock. Many are in a condition of severe strain when found, and contain minute cavities filled with liquid carbonic acid. They are liable, in consequence, to break or even fly into powder when warmed by the hand or struck. Though usually colourless, diamonds may be yellow, green, blue, or red, and the rays of radium cause colourless diamonds to become coloured. Some diamonds, but not all, are phosphorescent--that is to say, like the well-known luminous paint--after exposure to strong light they acquire the power of shining themselves for a certain time when removed to a dark chamber. And the curious thing is that, though themselves colourless, some give out blue, some green, some yellow, and some red light. The most wonderful, however, in this respect are the rare diamonds which become luminous merely by rubbing, and leave phosphorescent streaks on the cloth with which they are rubbed. This property is similar to the phosphorescence shown by other kinds of crystals when heated or when simply fractured.

Diamonds are readily distinguished from paste by the Röntgen rays, since they are transparent to those rays, whilst paste (or glass) is opaque to them. Radium also causes diamonds, but not paste, to phosphoresce. All diamonds are not equally hard, though they are the hardest of stones, and harder than steel, but not harder than the metal tantalum. Some Australian diamonds are known (from Inverel, New South Wales) which are so hard that at one time they could not be cut and polished; but only four years ago the rapidity of the wheels used in these processes was greatly increased, and these terribly hard diamonds were brought into subjection.

Thus it is clear that there are many extraordinary features of interest about the diamond, and that its brilliance and high price constitute only a small part of its fascination.

10. _Science and Fisheries_