Part 3
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_
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.
At Ismailia, on the Suez Canal, malaria was almost universal; in 1866 there were in a population of eight thousand, 2,300 cases. In 1897 there were over 2,000, and in 1902, when Ross was asked by the Prince d’Arenberg to visit the place and advise as to measures to be taken, there were 1,551 cases. Ross directed the filling up of the breeding pools. The marshes were filled up with sand, the irrigation channels were deepened or treated with kerosene oil (which spreads as a fine film, and chokes the gnat larvæ), and the cess-pits were rendered uninhabitable by chemical treatment. In one year the cases of malaria fell to 214, in 1905 they were only thirty-seven, and now the Suez Canal Company officially reports, “all trace of malaria has disappeared from Ismailia.” The same satisfactory results have been obtained in Port Said, in Khartoum, in Port Swettenham of the Federated Malay States, in Havannah City, in Panama, and, in fact, wherever intelligent conviction has led to the active and complete employment of the methods necessary for the destruction of the gnats. Under the British Government of India and the African and West India Colonies, little has been done. Why? Because of the handmaiden theory and the ostrich-like refusal of our officials to face and accept the master.
An even more wonderful and beneficent result has been obtained in the case of that terrible disease “Yellow Jack,” or “Black Vomit”--the yellow fever. Owing to the discoveries and definite proof by Ross as to the part played by gnats in malaria, the able medical men in the public service of the United States of America have thoroughly examined experimentally the mode of infection of human beings with the germ of yellow fever, and have conclusively proved that infection is solely and entirely due to the bite of one species of gnat--the Stegomyia fasciata. They have proved to absolute certainty that yellow fever is not carried through the air, nor by food or drink, nor by contact with infected persons or their cloths or emanations, but only by the fasciate gnat, a house-frequenting species, which sucks the blood of a yellow fever patient, and after twelve days, and not till then, becomes capable of imparting the infection to those whom it may stab or “bite.” The firm demonstration of this fact was not made without great devotion, courage, and self-sacrifice. In the ardour of their pursuit not a few of the experimenters risked and lost their lives. Among these the name of Dr. Lazear, of the United States Army, is prominent. He deliberately permitted himself to be bitten by a stray mosquito in a yellow fever hospital, in order to show that the insect could convey the infection. He was bitten on Sept. 13, 1900, and died on Sept. 25, having proved his point.
The actual germ, microbe, or minute parasitic organism which causes yellow fever, and is carried by the fasciate gnat, has not yet been detected. Nevertheless, without seeing and isolating the microbe, the medical men of America (Sternberg, Finlay, Carroll, and others) have, by destroying the gnat and preventing its access to men--especially to patients already infected, and, therefore, certain to infect the gnats and cause them to spread the disease--practically made an end of yellow fever in many great cities of the New World, where it was only six years ago an ever-present horror, striking men down with a suddenness and with a deadliness which paralysed human activity. Here, as in other cases, intelligent appreciation of the results of science by a governor or a municipality has saved thousands of lives. On the other hand, in Rio de Janeiro, “the opposition encountered by the sanitary authorities of the city from political factions and the ridicule to which they were subjected by the local Press” were insuperable (I quote from an official report), and so a few more thousand lives were sacrificed before the master was recognised and the proffered safety accepted. In Vera Cruz, in New Orleans, and in Panama yellow fever has been reduced to a vanishing quantity by removing the pools and tanks in which the fasciate gnat can breed, and by making use of wire-gauze to prevent the access of mosquitoes to houses, bed-chambers, drains, and baths, and especially to prevent not only their access to, but their egress from, the rooms and beds of patients already infected with disease.
In the city of Havannah, during the American occupation of Cuba (1900-1903), Colonel Gorgas reduced the death-rate due to yellow fever from an annual average of 751 to so small a figure as six. The same energetic and faithful administrator has been at work, with even more remarkable results, in the canal zone of the Isthmus of Panama since 1904. The attempt of the French to cut the canal was foiled chiefly by yellow fever and malaria. It is estimated that their effort cost quite 50,000 lives. Assisted by an able and enthusiastic staff, and charged with the task by a Government which comprehends the fact that the really “practical men” are the men who recognise science as the master (not as the negligible eccentric handmaid), Colonel Gorgas has banished the mosquito from his zone of occupation. As a consequence there is neither malaria nor yellow fever on the Panama works. In 1906 the total death-rate amongst 5,000 white employés on the Panama Canal works was only seven in the thousand. Further, in last April the daily sick-rate of the total force of about 40,000 people was only seventeen in the thousand. Colonel Gorgas declares that there is but little sickness of any kind among the Americans in the employ of the Panama Commission, and that they and their wives and children are fully as vigorous and robust in appearance and in fact, as the same number of people in the United States. There is no reason why the centres of wealth, civilisation, and population should not again be in the tropics, as they were in the dawn of man’s history.
12. _Malta Fever_
Mediterranean or Malta fever was for long confused with typhoid and other fevers. Our soldiers and sailors at Malta, Gibraltar, and Cyprus, as well as many frequenters of the African and Asiatic shore, were subject to this disease, and often incapacitated by it. In 1887 Colonel David Bruce discovered in the blood of patients the minute Micrococcus melitensis, which is its cause, and established the fact that it is a definite independent disease. The hospital at Malta has received as many as 624 patients in a year suffering from Malta fever from among the 8,000 soldiers on the island and the 12,000 sailors on the Mediterranean Station. And as they stay in hospital on an average for four months, this means 74,880 days of illness. This means a considerable loss to the State, as well as a large amount of personal suffering terminated, in some cases after two years’ sickness, by death.
The War Office, Admiralty, and Colonial Office applied in 1904 to the Royal Society of London to undertake a further investigation of this disease. The society sent out a small commission, which has been at work for three years, and has published seven volumes of reports. The problem before the commission was to discover the mode of infection by the Malta-fever germ (the Micrococcus melitensis), and thus, if possible, to arrive at a means of arresting the infection. Various hypotheses, guesses as to probable and possible methods of dissemination, were entertained and examined. As the germ occurs in the blood, it was naturally considered possible that gnats or other insects were the carrying agent. But negative results followed all experiments in this direction. Then it was found that the “germ” passes out of the body in large quantities by the renal secretion, and it was thought that it might be conveyed in a dried form with dust in the air. This also proved to be an incorrect supposition.
Next a very important discovery was made. The germ was found in the blood and the excretions of 10 per cent. of the goats which are kept in Malta as the sole source of milk, and are driven through the streets to supply customers, whilst 50 per cent. of the goats were found to have been infected at some time. Then the germ was found in the milk itself, and it only remained to prove by experiment that it was from the goats’ milk that human beings acquire the infection. A monkey fed with the milk of an infected goat acquired the fever.
The next step was to stop the consumption of goats’ milk by the soldiers and sailors in the hospital and barrack. Actually we were carefully feeding our invalid soldiers and sailors in the great hospital at Valetta with a highly poisonous infected fluid--the milk of the Maltese goat! The preventive measure--the stoppage of goats’ milk--only came into operation in July, 1906. In the first six months of that year there were thirty-one cases of Malta fever in every thousand of the garrison (numbering about 8,000 men). In the preceding six months there had been forty-seven cases per thousand. Now when the goats’ milk was stopped after July, 1906, what was the result? From July to December, 1906, there were only ten cases per thousand of the garrison. In actual numbers there were in July, August, and September in 1905 as many as 258 cases, whilst in the same months in 1906, after removal of goats’ milk from the dietary of the troops, there were only twenty-six cases, and these were probably due to the independent purchase of goats’ milk by soldiers outside the barracks. In the naval hospital until 1906 almost every patient who remained in the hospital a few weeks took the disease. Since the exclusion of goats’ milk not a single case has occurred.
The Director-General of the Medical Department of the Navy reports that there has been no case of Malta fever during the year among the sailors, and only seven cases among the soldiers up to the end of September, 1907.
Gibraltar had a fever of its own, identical with Malta fever. It has now been shown that it was probably introduced by the importation of goats from Malta for the supply of milk. This is likely, because the importation of Maltese goats ceased in 1883, and the fever began to disappear from Gibraltar in 1885, and finally vanished altogether in 1905.
In South Africa Malta-fever is common amongst the white population. It is probable, according to Colonel Birt, that it was introduced by means of infected goats imported from the Mediterranean. The soldiers, however, in South Africa are free from this disease, excepting those who have already contracted it in the Mediterranean, since in South Africa goats’ milk does not enter into the dietary of the soldier. It is the civilian population which suffers.
13. _A Cure for Sleeping Sickness_
Diamonds and sleeping sickness are both special African problems. It was owing to the proposal to employ natives from Uganda in the South African diamond mines that the Colonial Secretary (Mr. Chamberlain at that date) asked the Royal Society to say whether the sleeping sickness which had broken out with terrible violence in Central Africa constituted an obstacle to that employment, on account of the danger of introducing the disease into South Africa. The Royal Society advised the Government not to allow the transport of natives from the infected districts of Uganda, and sent out a commission to Central Africa to study the disease. The result was the discovery by Colonel Bruce of the parasite of sleeping sickness called Trypanosoma--a kind previously known in some other diseases--and of the fact that it is a tsetse-fly which carries it. A quarter of a million natives have died in Central Africa within the last six years from sleeping sickness. The Tropical Diseases Committee of the Royal Society has started an inquiry into the action of drugs on the parasites (known as trypanosomes) which cause sleeping sickness and the horse and cattle disease of the “fly-belts” of South Africa.