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
Science, the knowledge of the vast system of orderly, inexorable activities under which we exist, and of which we, and all that we can apprehend, are but more or less significant parts, is not only to be regarded as a gratification of our curiosity, as food for our imagination, and the basis of our philosophical theories. It is, in addition to these, a thing of unparalleled importance to the immediate daily welfare of every man, woman, and child, and upon its due cultivation and use depend the future welfare, even the existence, of whole races of mankind. It is a startling fact that so few of those who undertake to lead and to legislate for the people of this country have any real conviction, or even a dim understanding of this truth.
In November 1906 a Committee appointed by the Government took evidence as to the desirability of continuing the international investigation of the North Sea, upon which Great Britain entered five years ago in conjunction with other Northern States. Only a few weeks before, a number of scientific experts engaged in this study of the North Sea, with a view to gaining such knowledge of that great “waste of waters” as may help the nations of adjacent lands to draw from it stores of food without destroying the source or recklessly injuring the supply, were entertained at dinner, at the Guildhall, by the City Fathers, and treated to speeches by hereditary legislators. The view expressed by these speakers was that the interests of the great fishing industry and of the fish trade were best understood by the practical fisherman. Science was a “handmaid,” useful in her place, but not to be permitted to undermine established interests and the hoary wisdom of the practical man, her employer. A German expert of high official position, one of the guests, took a different line. He was astonished, even shocked, that Great Britain, the State most largely concerned in the North Sea fisheries, should be hesitating about continuing to take part in the international investigation. In Germany, he said, they took a different course in such matters. Men of business and practical legislators, when called upon to deal with an important problem, sought first of all for scientific knowledge of the conditions in question, as complete and thorough as possible, and then proceeded to act upon the sure foundation gained. More knowledge, much more knowledge as to the causes and conditions at work in regard to the life and movements of fishes in the North Sea was needed. The work of the International Committee must be continued, and his (the German) Government would certainly continue to do its share of the work.
The contrast in the British and the German attitude towards science is what is interesting in this episode. It is true that men of science in this country have to be content to take a very modest part in public affairs, and to allow politicians and self-styled “practical” men to treat science as “a handmaiden”—thankful when science is not regarded as an enemy. But they know well enough, and those who are really “practical men” know, that science is no handmaiden, but in reality the master—the master who must be obeyed; who alone can give true guidance; who alone can save the State. The sooner and the more thoroughly the people of this country have recognised this fact, and insist upon its unqualified acceptance in practice by their representatives and governors, the better for them and their posterity.
11. Discoveries as to Malaria
Recent scientific work, discovery, and application to practical affairs of the results of discovery, in regard to three great obstacles to human life and prosperity illustrate the vital importance to the state of scientific research. The obstacles in question are the diseases known as malaria, yellow fever, and Mediterranean, or Malta fever. It is now twenty-five years since Dr. Laveran, of Paris, discovered that malaria, or ague, is caused by a very minute parasite which exists in the red blood corpuscles of those stricken with the fever, and suggested that it is probably carried from victim to victim by blood-sucking mosquitoes (gnats). Major Ross, of the Indian Army, who has been rewarded for his discovery by the Nobel prize, determined to find out what gnat it is which carries the malaria-germ from man to man, and by most persevering experiment and microscopic examination showed that it is not the commoner gnat or mosquito (Culex), but the spot-winged kind (Anopheles), which alone can spread the malarial infection. But Major Ross is, before everything else, a medical man, and his great purpose has been to apply his discovery to the prevention of disease.
Whole regions of the earth’s surface are rendered dangerous, or even uninhabitable, for civilised men by malaria; in other words, by the Anopheles mosquito. Accordingly, Ross set to work to find the best means of destroying these agents of disease. He found that the Anopheles gnat breeds in natural collections of water lying upon the surface of the ground in open country, and not as many common varieties of gnats do, in vessels and cisterns in houses. The pools frequented by the malaria-carrying gnat are small and easily drained. The obvious direction of science, therefore, was to remove or to cover up these pools wherever they were found in the neighbourhood of human habitations. Although Major Ross made his discoveries in India, and although he opened a campaign against malaria by removal of surface pools in the Colonies of West Africa—“the white man’s grave”—twice visiting the chief British settlements—only half-hearted, incomplete measures have been taken, insufficient funds have been expended, and a supine executive and half-incredulous officials have failed to do more than partially reduce the prevalence of malaria in those regions. On the other hand, where intelligent officials have understood and accepted the clear results of science in regard to malaria, the most striking and satisfactory consequences have followed.