From an Easy Chair

by Sir E. Ray Lankester

Thus we see that a pearl is not only a disease or abnormal growth caused by a parasite, but is actually an elaborately formed tomb or sarcophagus, in which the parasite is enclosed layer upon layer. This mode of disposing of parasites and other intrusive bodies is not unusual in animals. The terrible little flesh-worm—the Trichina—which causes the death of rats, pigs, and men who eat raw meat, is sometimes conquered in this way. It is found in the muscles (flesh) of man and animals enclosed in little pearl-like sacs, half the size of a hempseed, and it dies there, unless the invaded animal should die, and its flesh be eaten (as raw ham for instance) by another animal. The burying of inconvenient corpses in plaster of paris, corresponding to pearls as we now know them, has been a method of concealment occasionally adopted by criminals. On the whole, pearls have not very pleasant associations.

The history of the special parasitic worm which invades the beautiful little pearl-oyster of Ceylon has recently been followed out by skilful naturalists. There, too, a smaller oyster-eating fish of a peculiar kind, and a larger fish which eats the first fish, are necessary for the reproduction and multiplication of the pearl-producing parasites. The new Ceylon Pearl-Fishing Company has, therefore, to see to it that both these kinds of fish are encouraged to live in the sea near where the pearl oysters are found, and it is their object to increase the parasitic disease by which pearls are formed, and ensure an abundance of parasites.

An interesting new method has been recently applied to the examination of pearl oysters for pearls. The Rontgen rays are used to produce a skiagraph (such as surgeons use in searching for a bullet) of the pearl oysters when brought into harbour. They are thus rapidly examined one by one, without injury, and the shadow-picture shows the pearl or pearls inside those oysters which are infected. The pearlless oysters are returned to the depths of the sea, whence they came—those with small pearls only are kept in special reserves or sea-lakes, in order that the pearl may grow in size, whilst only those with good-sized pearls are opened at once, in order that the pearl may be extracted and sent to market.

There were great findings of pearls in the fresh-water pearl mussels of the Scotch rivers in former days. In the last forty years of the eighteenth century these pearls were exported from Scotland to France to the value of £100,000.

In the eighteenth century not only did they get their pearls from European rivers instead of from the East; but, instead of being excited about the artificial production of diamonds, they were driven wild with astonishment by the demonstration of the volatilisation of these stones—the disappearance of diamonds into invisible vapour when sufficiently heated. That the hardest stone in nature could be thus dissipated into thin air seemed incredible. On Aug. 10, 1771, a chemist named Rouelle invited to his laboratory to witness this wonder a company comprising the Margrave of Baden and the Princess his wife, the Dukes of Chaulne and of Nivernois, the Marchionesses of Nesle and of Pons, the Countess of Polignac, and some members of the Academy of Sciences, including the great chemist Lavoisier. Four diamonds—the largest belonging to the Count Lauraguais—were submitted before the eyes of all to the heat of a furnace, and in three hours had completely evaporated. There was, no doubt, room here for a mystification and for the abstraction of the diamonds with a view to dishonest appropriation. But no such purpose existed. The experiment was a genuine one, and Rouelle and his brother were honest investigators. They established the fact, now demonstrated as a lecture experiment, that the diamond is volatilised at very high temperatures. A more celebrated “evaporation” of diamonds—that which is known as “the affair of the Queen’s necklace”—took place a few years later in Paris, when no scientific investigation was connected with the embarrassing disappearance of the Royal trinket.

35. A King Who was a Zoologist

The King of Portugal, Carlos di Braganza, who was assassinated in the spring of 1908, was one of the most gifted and vigorous men of his age, fearless and intelligent to a rare degree, good-hearted, and devoted to the welfare of his people. If any man were justified in having no fear of outrage because he was conscious that his uprightness was proved and known to all men, his benevolence experienced by all, his ability and vast knowledge recognised by all, Dom Carlos was that man. Fanaticism, however, takes no account of the virtues of its victims. Until society has invented a method for keeping instruments of destruction out of the reach of dangerous, more or less maniacal individuals, all those who excite the fanatic’s brain, even by the excellence and nobility of their lives, risk death whenever they trust themselves to the tender mercies of a crowd. Psychology may one day enable us to detect, and improved supervision of children enable us to segregate before it is too late, the latent assassins in our midst. If they have not a king as their quarry their reason is palsied by a president, and were there no presidents, they would become homicidal in the presence of a prefect or a policeman—even of a professor.

Some four years ago I had the honour of conducting Dom Carlos round the Natural History Museum in Cromwell Road. He arrived without attendant or escort, and I passed two hours alone with him. I had been told that he was a great shot and fond of natural history, that he played every athletic game, rode, and swam better than the best, that he was a fine water-colour painter, a real artist—and a first-rate musician and singer. I was astonished at his knowledge and personal experience in natural history. His burly form and bright, honest face gave me a most agreeable impression, and when he said (as I had been told he would) to each explanation of a specimen upon which I ventured for his edification, “I know! I know!” felt that it was true, and that he really did know. “I have shot thirty of them in the south of my country,” he said of some rare bird. “I know! I know! I have described a new species like that in my book on the birds of Portugal. I shall send it to you!” was his comment on another. When we came to some wonderful coral-like specimens—sea-pens and sea-feathers, dredged in the deep sea and preserved in spirits, for exhibition in the Museum—he said, to my astonishment, “Those are very bad. I get much better than those in my yacht off the Portuguese coast. I preserve them myself; it is a real art. I shall send you some.” I said they would be a very welcome addition. “Yes, I know! I know!” he said. “Would you like some fishes, too? The Prince of Monaco has some fine things, and he led me to collect also myself. I have now many things better than his. I shall send you some fishes, too.” And he did. A few months after his return to Portugal he sent to the Museum a large collection, preserved in spirit, which included many very fine and interesting specimens of deep-water Atlantic fishes; also his work, with coloured plates, on the Birds of Portugal, and a most remarkable publication on the tunny fisheries of the South Coast of Portugal—giving a careful survey of the waters, sea bottom, currents, fauna, and flora in correct, expert form, such as might issue from a Government Fisheries Board, but in this case done, as modestly indicated on the title-page, by the Head of the State himself, “Dom Carlos di Braganza.” He went into the work-rooms of the Museum, where some new fishes were being drawn, and conversed with the naturalist in charge, and criticised the drawings. He saw everything, appreciated everything, and then looking at his watch, said, “I have only five minutes to get to a lunch party. Thank you very much for the most delightful time. I should like to stay all the day; it is a splendid place,” and was off in his brougham.

I exhibited the specimens and books sent by his Majesty for some weeks in the Central Hall of the museum, before they were incorporated in the great collection, for I felt that it was a rare and interesting thing that a king should not merely take a sportsman’s pleasure in birds, beasts, and fishes, but actually be, so to speak, “one of us”—a zoologist who discovers, describes, and names new things. The Prince of Monaco is the only other head of a State who is a serious scientific naturalist. He has built and endowed a magnificent museum and laboratory at Monaco, where his skilled assistants carry on researches and look after the extremely valuable and important collections which he has himself made in a series of cruises in the Atlantic extending over many years. He has not only employed capable naturalists to help him, but is himself the chief authority and an original discoverer in “oceanography,” the science of the great oceans.

A year or so ago, when Dom Carlos visited Paris, a special fête and reception was organised in his honour at the “Muséum d’Histoire Naturelle,” in the Jardin des Plantes. The “Museum” of the Jardin des Plantes is a very remarkable institution, including a zoological and botanical garden, laboratories of chemistry, physics, and physiology, besides the great collections of minerals, fossils, skeletons, and preserved specimens of animals and plants. It is governed by the professors and the director who are in charge of the garden, the laboratories, and the collections, and owes its dignity and its celebrity to the distinguished men of science who for a century and a half have made discoveries and taught there. They are not subject to a board of eminent and wealthy persons, nor is the administration of the antiquities at the Louvre and of the National Library muddled up with that of the great scientific workshop of Natural History.