FOOTNOTE:

[8] I am indebted for the figures (not the diagrams) illustrating Chapters XVII., XVIII., XIX. to the report by Mr. Thomas Wilson on the Swastika—in the Smithsonian Reports, 1894. Those interested in this subject will find a vast store of information in that report.

CHAPTER XX

COAL

COAL is so much "a matter of course" in our daily life that most people are only now, when its supply is becoming precarious, anxious to know something of its nature and history. By the word "coal," or "coles," our ancestors understood what we now distinguish as "charcoal," prepared from wood by the "charcoal-burner," or "charbonnier," as the French call him. What we now call "coal" was known to them as "sea-coal," and, later, as "black" or "stone cole," to distinguish it from "brown coal," known nowadays as "lignite," though the name "stone coal" is locally applied in England to that very hard kind of black coal also called "anthracite," of which jet is only an extremely hard and dense variety found in small quantities in the oolitic strata of Whitby, Spain, and other localities.

It is on record that in the year 1306 a citizen of London was tried, condemned, and executed for burning "sea-coal." This severe treatment was held to be justified by the poisonous and otherwise injurious nature of the smoke produced by fires of sea-coal. I have not met with any records of the earliest digging for and trade in "sea-coal," but presumably it was obtained near the coast in the North of England and brought to London by ship—hence its name. The coal-trade of Newcastle began in the thirteenth century, but, owing to an Act of Parliament in the reign of Edward I forbidding the use of sea-coal in London, did not become important until the seventeenth century. It came very gradually into use, and we find that Evelyn (the diarist) in 1661 noted the withering and bad condition of rose-bushes and other plants in London gardens, which he attributed to the pestilential action of the smoke given off by the newly introduced "sea-coal" which was increasingly used as fuel in London houses. The sea-coal was not yet largely, if at all, used in the production of iron; and Evelyn as a forest-owner and lover of trees, has much to say about the necessity for attention to the cultivation of our forests in connection with the iron industry which then flourished in the Weald of Sussex; charcoal procured by the slow burning or roasting of wood being the fuel used in the smelting furnaces, whilst the ore was the orange-brown wealden sand. It was during the eighteenth century that what we now call simply "coal" came rapidly into use—not only for domestic heating, but for furnaces of all kinds employed in industrial enterprise, and, at a later date, for the earlier and later forms of steam-engines. The smoke of the new coal was everywhere regarded as a terrible nuisance, and a source of injury to both animal and vegetable life. The poisonous action of coal-smoke is not due to the finely divided black particles of carbon of which it largely consists, but to the sulphuric acid derived from the small quantities of sulphur present in coal. It is calculated that more than sixteen million tons of coal are annually used in London alone for heating purposes, and that 480,000 tons of black carbon powder are discharged over London by its chimneys every year, together with very nearly the same weight of poisonous sulphuric acid!

What, then, is this "sea-coal" or "coal" of our modern life? We all know its black, glistening appearance, and more or less friable character. Its nature and origin are best conveyed by the statement that it is very ancient "peat," compressed and naturally changed by chemical action and retaining little or no trace of its original structure. Peat, as we know it from the low land of English and French river valleys and the bogs of Scotland and Ireland, is formed by the annual growth and death of "mosses" of several kinds and of other accompanying vegetation. It retains the woody forms of the vegetable growths which constitute it, and they are often but loosely adherent to one another. Peat may be merely a growth of the past five years, but is sometimes many thousand years old. Older than peat, and more caked and compressed, is lignite, or brown coal, which occurs on the Continent of Europe, also in South Devon and elsewhere, in geological strata newer than those which yield our black coal. Then we have the most important class of black coals which are known as "bituminous coals," because they soften when heated and form hydrocarbons of both viscid and gaseous nature. They are used for domestic purposes, and wherever flame is desired. They are, in fact, the "lumps of coal" familiar in our scuttles. The "bituminous coal" with the greatest amount of hydrogen in it is the cannel or candle coal, so called from its bright flame when burning. This kind is especially valuable for gas-making, and of smaller value as fuel. The term "anthracite" is reserved for a hard, stone-like coal which is very nearly pure carbon (ninety per cent). This class of coal burns with a very small amount of flame, gives intense heat, and no smoke. It is used in drying malt and hops.

Like all woody matter, that from which peat is formed consists of a combination of the elements carbon, hydrogen and oxygen; and these remain in somewhat changed chemical union in the brown coal, bituminous coal, and anthracite. The carbon and a varying and small proportion of the original hydrogen of the woody peat, are the important elements in coal; and we may well ask how they come to be produced as a black or dark brown mass from dead vegetable growths which are often bleached and colourless. It is true that vegetable refuse does not necessarily blacken when left to itself. We know that by roasting or charring wood (or animals' flesh or bone) we can drive off the elements oxygen and hydrogen and nitrogen (if there), and obtain a black mass of carbon (so-called charcoal). That blackness is the actual true tint of carbon. The dead weeds and leaves at the bottom of a stagnant pond break down and form a pitch-black mud. They would not, and do not, go black if exposed to the oxygen of the atmosphere; but at the bottom of a stagnant pond or in a refuse heap they are excluded from the air, and a microbe—a bacterium which has been carefully studied, and is of a kind which can only flourish in the absence of free oxygen—attacks the dead weeds, producing by change of their substance marsh-gas and black carbon, the black mud emitting bubbles of gas which one may stir up with a pole in such a pond. This chemical attack by anaërobic bacteria goes on in the deeper layers of all marshes and stagnant pools, remote from the oxygen of the air; and it is fairly certain that the black coal which we find in strata of great geological age was so produced by the action of special kinds of bacteria upon peat-like masses of vegetable refuse. Indeed, by studying microscopic sections of coal, numerous forms of bacteria have been recognized which might be capable of effecting such chemical changes. On the other hand, we must remember that it is not possible to conclude by form alone as to what subtle chemical work a bacterium or bacillus or micro-coccus may be, or may have been, carrying on. The peat-like deposits which became carbonized and so formed the "coal" were probably masses of algæ, mosses and soft aquatic plants, which were brought down and accumulated in swampy, forest-covered ground about the mouths of rivers, the deposit being covered in owing to rapid oscillations of level by beds of sand or clay, followed by new growth and deposit.

Our British coal and a good deal of foreign coal is found in certain stratified rocks of the earth's crust known as "the Carboniferous System," about 12,000 ft. thick, consisting chiefly of very dense limestone. The "seams," or stratified beds of coal, occur in sandy rock known as the "Coal Measures," and vary in thickness from a mere film to 40 ft. Above the Carboniferous System are later deposits, some 14,000 ft. in thickness—the Permian, Triassic, Jurassic, Cretaceous, and Tertiary strata. Below them we find stratified deposits containing fossilized remains of plants and animals, to a depth of another 40,000 ft.: they are the Devonian, Silurian, and Cambrian "systems" or series of strata. Coal of a workable nature is found in many parts of the world in the beds or strata of later age than our Coal Measures—namely, those of Jurassic, Cretaceous, and Tertiary age.

Coal is so valuable and used in such vast quantities by modern man that, though procured at first from beds lying at or near the surface, it has been found remunerative to mine far into the depths of the earth's surface, where its existence is ascertained, in order to procure it. A depth of 4000 ft. is apparently the limit set to such mining by the increase of temperature in mines which penetrate to that extent below the surface. In 1905 the annual output of British coal-mines was in round numbers 230,000,000 tons. It is certain that there is a limit to this production, but not possible to calculate what that limit may be, owing to the uncertainty as to the future working of coal-fields as yet unexplored.

Such questions have been, and are being, considered by experts on behalf of the Government. A matter of interest of another kind is that in and associated with the coal seams of our Coal Measures, fossilized remains of peculiar fern-like trees, ferns, and other strange plants, and of very peculiar, extinct newt-like animals (as large as crocodiles) are found in great variety. The notion that the toads occasionally found embedded in the black mud of a coal-yard or even in a fractured lump of coal are survivals from the time—many millions of years past—when the plants and animals of the Coal Measure swamps were living, is a baseless fancy. The toads so found are of the kind or species now living on the earth—totally different from those whose bones occur in the Coal Measures, and the presence of such modern toads embedded in black slime, in coal-heaps in store-yards, or even in coal-scuttles, is only what may be expected to occur and does occur in damp quarries and other places where these familiar little beasts love to hide.

CHAPTER XXI

BORING FOR OIL

CLOSELY similar to coal in chemical matter—that is to say, consisting chiefly of definite chemical compounds, called hydrocarbons, built up of only two elements, carbon and hydrogen, and of no other—is a very remarkable class of mineral substances known to the ancients as "bitumen." In its widest sense, it includes "natural gas," the variously mixed liquids called "petroleum" and the solid "asphalts." In ancient times the more fluid kinds of petroleum issuing from the ground in South Russia and Persia were called "naphtha," and that name is still applied to the more volatile hydrocarbons obtained by the distillation of such substances as coal-tar (the residue of the extraction by heat of commercial gas from coal), bituminous shale, petroleum, wood and some other bodies which owe their existence to the activity either of living or of long-extinct and "fossilized" plants and animals.

The bitumens, together with coal, present in their natural state a very large variety of inflammable constituents—gaseous, liquid, and solid hydrocarbons; but, when "distilled" at various temperatures and under conditions determined by the manufacturing chemist, they yield a still larger series of pure separable bodies, which have been minutely studied and classified according to their chemical constitution. They are produced in great chemical factories in large quantities for use in the most diverse ways invented by human ingenuity. Thus natural gas—superseded by distilled coal-gas—has served for fuel and for illumination: refined petroleum serves not only for those uses in general, but as the special source of power in the engines of motor-cars and aeroplanes. A wonderful solid crystalline wax-like substance, paraffin, as white as snow, is distilled in enormous quantities (nearly three million tons a year) from "bituminous shale" or "oil-shale" in this country alone. It can be obtained in soft (vaseline) and liquid forms, and in fact the "paraffin series" recognized by chemists starts from the gas "methane," or marsh-gas, and comprises some thirty kinds, leading from gas to volatile liquids, thence to viscid liquids, to butter-like solids, and up to hard crystalline substances which melt only at the temperature of boiling water. Endless chemical manufacturing industries—e.g., those of dye-stuffs and explosives—depend upon the chemical treatment of these paraffins and of various bodies obtained as secondary products in their preparation. Benzine and aniline are chiefly obtained from coal-tar. The oils and waxes of quasi-mineral origin have a great advantage over vegetable and animal oils in many uses, since they are not liable to become "rancid"; that is to say, to decompose owing to the action on them of bacteria. A marked difference between the paraffins (often distinguished, together with the "olefines," as "mineral" oils) and the oils and fats found in living plants and animals is that they do not "saponify"; that is to say, they do not form those combinations with alkalis and other bases which are called "soaps," nor can they serve as food to man or any other animal. They are not acted on by the digestive juices.

From ancient times natural deposits or outpourings of "bitumens" have been known and used by mankind. The Assyrians and other early peoples of the East used "asphalt" (translated by the word "slime" in the English version of the Bible) in place of calcareous mortar in building; and to this day it is used largely in this country as a "damp-course" in walls built of brick. Great deposits of asphalt are found in Central America and some of the West Indian islands, and "quarried" for commercial purposes. The great pitch-lake of Trinidad yields an abundant supply. In the Val de Travers, in the Canton of Neuchatel (Switzerland), a rich deposit is worked which, mixed with earthy material, forms a road-making concrete, largely used in London and other cities, and also for main roads in country districts. The ancient Egyptians used asphalt for embalming the dead. But the ancients also knew natural springs of liquid bitumen—that which nowadays we call petroleum—some of them freely flowing like water, which would take fire and burn for long periods, and were described as fountains of "burning water." We find, as we pass from the Middle Ages to the days of geographical exploration, records of such springs of inflammable oil and of natural inflammable gas in all parts of the world—Japan, China, Burma, Persia, Galicia, Italy (Salsomaggiore), Central and North America, and of not a few in these islands—for instance, in Shropshire, Derbyshire, Sussex, Kimmeridge and various sites in the southern counties. The oil was, until the middle of the last century, valued chiefly as a medicinal application, and "Seneca oil" and "American medicinal oil" were largely sold and used as an embrocation in the United States.

We owe the introduction of the name "petroleum" to Professor Silliman, who in 1855 reported upon the "rock oil or petroleum" of Venango County, Pennsylvania. The first attempt as a commercial enterprise to obtain rock-oil or petroleum by boring into the strata in which there was local evidence of its existence in greater or less quantity, was made in 1854 by the Pennsylvania Rock Oil Company. After some unsuccessful attempts, when the drilling had been carried to a depth of 69 ft. the tools suddenly dropped into a subterranean cavity, and on the following day the well was found to have "struck oil," and twenty-five barrels a day were yielded by that well for some time. From here the industry spread over the States and Canada, and in 1908 the year's yield was 45,000,000 barrels.

Since 1870 the industry has spread all over the globe—Russia, Galicia, Rumania, Java, Borneo and Burma being prominent sources of the oil supply of the world. The raw petroleum of different localities differs in each case in the amount of solid paraffins and olefines dissolved in the liquid paraffins. Other substances also are dissolved in it in variable amount—such as benzene, acetylene, camphene and naphthalene. The fact that the oil, when reached by a boring, is often found to be under a considerable pressure, so that it rises and flows from the surface of the well, or even may shoot up as a great fountain, is an important feature in the oil-seeking industry, though the supply depends largely on pumping and not necessarily on natural flow. The borings when made, act like Artesian wells, and sometimes are carried to a great depth. Those in Pennsylvania vary in depth from 300 ft. to 3700 ft., according to the distance below the surface at which the oil-bearing strata (usually a sandstone) is situate. As in the case of an Artesian well, the boring is in the first instance an exploration subject to uncertainty as to "striking" the desired liquid, but the uncertainty is greater in the case of the search for oil than in that for water. The water-well is also far less likely to "give out" when once flowing than is that bored for oil, which, even if at first successful, may be soon exhausted owing to the small area of the oil-bearing strata tapped. A cause of the high pressure in many oil-wells is the gas which accompanies the oil. The pressure may amount to as much as 1000 lb. to the square inch. In the Northern Caucasus spouting wells caused by the high pressure of gas in the boring are frequent. A famous fountain-well in that region, which began to flow in August 1895, threw up 4-1/2 million gallons a day, gradually diminishing during fifteen months until it became exhausted. At first, when boring was introduced, such outbursts led to an enormous loss of the oil, for there was not sufficient means of storing or transporting it. Ordinary cartage in barrels was the earlier method; then followed tanks on railway trains and canal boats; and this has been supplemented by the use of pipes along which the oil is pumped from the well to the refinery. In Pennsylvania there are said to be no less than 25,000 miles of such pipes in use for the distribution of petroleum.

It will be obvious from what is here stated that the attempt to discover an oil-supply in Derbyshire must not be regarded, at present, as more than a praiseworthy and interesting enterprise. There is no room for doubt that the best expert opinion has been brought to bear on the matter. A small quantity of petroleum has already been raised; but whether the flow will be sufficient to cover the expenses of the boring, and how long the flow may last, or how much it may amount to, are matters quite impossible to foretell. In any case, it is in the highest degree improbable that such an abundance of oil will be obtained as to count much, if at all, in the world's production of petroleum. It must also be remembered that products similar to those yielded by petroleum are already extracted in quantity as a remunerative industry by the distillation of oil-shales in various parts of the United Kingdom; and that there are oil-shales in this country still unworked. So that we need not be in despair if we do not tap an oil-spring of any importance close to hand. The world's supply is still open to British enterprise. Another reflection of some importance is that these world-wide sources of rock-oil or petroleum are likely to be exhausted by exploitation much sooner than are the coal-fields of the world. We cannot rely on their long duration.

CHAPTER XXII

THE STORY OF LIME-JUICE AND SCURVY

FROM mediæval times onward a serious constitutional disease—a morbid condition of the blood and tissues—has been known by the name "scurvy," and the word "scorbutic" has been coined from it. It is to-day practically unknown in the ordinary conditions of civilized life, but formerly was common, and the cause of disablement and of frightful mortality in ships' crews, beleaguered cities, armies on campaign, and war-stricken regions. It begins with a certain failure of strength. Breathlessness, exhaustion, and mental depression follow. The face looks haggard, sallow, and dusky. After some weeks the exhaustion becomes extreme; the gums are livid, ulcerated, and bleeding; the teeth loosen and drop out; purple spots appear on the skin; ulcers break out on the limbs; effusions of blood-stained fluid take place in the great cavities of the body; profound exhaustion and coma follow; and death results from disorganization of the lungs, kidneys, or digestive tract. It was recognized in early times that the disease was dependent on the character of the food of those attacked by it; and not the least of the horrors accompanying it was the terror caused by the well-founded conviction that the appearance of a single case in a ship's crew or other specially circumscribed community was an unfailing index, and meant that all were likely within a few days—owing to the enforced identity of their food and conditions of life—to develop the disease. Often, in past centuries, a half or two-thirds of a ship's company have been carried off by it before a port could be reached and healthy food and conditions of life obtained. At the present moment in view of the actual condition of Europe, it is a fact of very grave importance that scurvy is known to break out and cause a terrible mortality among civil communities in time of scarcity—especially in prisons, workhouses, and other public institutions, which are the first to suffer deprivations when food is scarce.

Three hundred years ago it was held that fresh vegetables and fruit-juices were both a cure for and a preventive of scurvy, or "anti-scorbutic." But the fact was not appreciated by Army and Admiralty officials that dried vegetables, even of kinds which were held to be especially "anti-scorbutic," would not serve in place of fresh ones. In 1720, dried "anti-scorbutic" herbs were supplied to the Austrian Army when suffering from scurvy; but they were of no avail, and thousands of the soldiers perished from the disease. A few years later, the British Lords of the Admiralty (actuated by a spirit of blundering parsimony) proposed to supply the Navy with dried spinach, although it was well known that dried vegetables were useless against scurvy. In the American Civil War, 1861-1865, in spite of this knowledge, large rations of dried vegetables were supplied to the armies, and failed to prevent outbreaks of scurvy. Even at the present day so little attention has been given of late years to the subject, that many ignorant officials, upon whose action the life of thousands depends, regard dried vegetables as equivalent in value to fresh!

A great advance was made in the second half of the eighteenth century, when the British Admiralty became convinced by the repeated experience of its officers that "lime-juice" is a specific remedy and preventive for scurvy, and, in spite of the great expense and difficulties entailed, adopted its use officially. In those days of sailing-ships, long voyages (such as those of Captain Cook) were safely carried through without serious outbreak of scurvy so long as a ration of so-called "lime-juice" (about one ounce) was swallowed each day by each sailor. But it was not until the beginning of the nineteenth century that the disease was practically eliminated from the Navy by the introduction (after many foolish delays) of a general issue of what was called "lime-juice."

The complete control and elimination of scurvy by the use of so-called "lime-juice" sufficed to carry us on until the introduction of steam navigation, when it became superfluous owing to the fact that long absence from land, where fresh food could be obtained, ceased to be usual. Moreover, after a mutiny on the part of our defrauded sailors, better food and greater variety of it was secured for them, and the profits of murderous contractors were stopped.

The history of outbreaks of scurvy for the last century is practically confined to the experiences of Arctic Expeditions and the campaigning of troops in remote or devastated regions. So little had scurvy been investigated, or any serious study made of the nature of the remedial and preventive action of lime-juice, that up to the year 1914 it was regarded as a matter of course that the acid, the citric acid, of lime-juice was what gave to it its virtue, and samples of lime-juice supplied by contractors were tested solely as to the percentage of that acid present. Eminent medical authorities proposed to use crystals of citric acid in place of the juice; others declared that vinegar would do just as well; others, in spite of the overwhelming record as to the value of lime-juice, held that scurvy was due not to the absence of a food constituent—supplied by fresh vegetables and fruit-juice—but to a peculiar poison present in the salted and dried meat served out as rations; others again, without any study of the disease, have expressed the opinion that it is due to a bacterial micro-organism.

A blow to the easy-going belief of the Admiralty that they had mastered and made an end of scurvy was struck when scurvy broke out (60 cases among 122 men) in the expedition to the North Pole which sailed in May 1875 in the Alert and the Discovery, under the command of Sir George Nares. The expedition had to return prematurely after seventeen months' absence, and a committee was appointed to inquire into the cause of the outbreak. The stores of food and of lime-juice were shown to have been ample; and the action of the leader in equipping his sledging parties was in accordance with the judgment and experience of successful explorers who gave evidence. The cause of the outbreak remained a mystery. The firm belief in the anti-scorbutic powers of "lime-juice" was shaken, and this unfavourable opinion of its value has been confirmed by medical officers who, during the recent war, have been confronted by outbreaks of scurvy. These outbreaks occurred among troops who, in military circumstances which rendered an adequate supply of fresh meat and vegetables impossible, were supplied with lime-juice prepared from the West Indian "sour-lime."

Under these circumstances, an experimental study of scurvy has been carried out during the last four years by a group of workers at the Lister Institute, together with a historical inquiry as to the use of lime-juice. The reports of these investigators have very great practical value and far-reaching interest, as showing what disastrous results may arise from inaccurate use of a word, and the neglect to ascertain the exact nature of the material thing upon which the issue between life and death may depend.

Here let me say that the staff of the Lister Institute for medical research has done work in its laboratories in Chelsea Gardens of the very greatest national importance during the war. It was founded by public subscription, and has now an endowment of some £10,000 a year. Sir David Bruce, the chairman of its Council, gives in the Report of the Governing Body for 1919 a very striking summary of the work done in the laboratories and by the staff of the Institute. The successful investigation of trench fever and of tetanus, of the destruction of lice, and of the effects of cold storage on food, besides the study of scurvy and other diseases due to deficiency of what are now called "accessory food factors," are, we learn, the chief matters in which the Lister Institute was engaged in the year 1918-19. Besides this, however, at its farm at Elstree it has prepared and supplied to the War Office, the Admiralty, the Overseas Forces, and the Local Government Board more than a million doses of anti-toxins (diphtheria and tetanus), bacterial vaccines (cholera, plague, influenza), and other similar curative fluids—requiring for their safe production the highest skill and most complete knowledge of recent discovery. And this is only a sample of what the Lister Institute has been doing for many consecutive years.

Now we return to the investigation of scurvy. Within the last ten years the fact has been established (which was more or less guessed and acted upon by medical men of past days) that, in order to maintain health, the diet of man and of many animals must contain not merely the necessary quantities of meat or cheese-like bodies, of fat and starch and sugar, but also minute quantities of accessory food-factors which it is convenient to term "vitamines." The name serves (though its etymology is unsatisfactory) to indicate certain "proteids" or highly complex nitrogenous compounds which are only to be obtained from fresh and uncooked or slightly heated vegetables and from some foods of animal origin. These "vitamines" are destroyed by heat and by desiccation. They have not yet been isolated though in some cases extracted in a nearly pure state. Their presence or absence is demonstrated by careful experiments in feeding animals, such as guinea-pigs, with weighed quantities of different foods. The "vitamine" is often found to be present only in one part of a seed or fruit or special kind of fat liable to be rejected in food preparation. An important fact is that it may not amount to as much as one-ten-thousandth of the weight of the food in which it occurs; and the part containing it may be overlooked and rejected, or its value destroyed by heat or by desiccation. A committee on these "accessory food-factors" is carrying on experiments at the Lister Institute. Dr. F. G. Hopkins, F.R.S., who first discovered the importance of one of these factors in feeding young rats, is the chairman, and Dr. Harriette Chick is the secretary. Three kinds of these vitamines, or accessory food-factors, have up to this date been recognized. The first is the anti-neuritic or anti-beri-beri vitamine. Its principal sources are the seeds of plants and the eggs of animals—yeast-cells are a rich source of it. Where "polished rice," as in the Far East, is the staple article of diet, to the almost entire exclusion of other food-stuffs, lassitude and severe pains like those of rheumatism set in, and a whole colony or shipload of Chinese "coolies" may be disabled. The disease is called beri-beri, and it can be cured by administering that part of the rice-grain (the skin and germ) which is removed by "polishing," and unfortunately is just that part which contains the needful vitamine. It exists in very minute quantity, amounting to only one part in ten thousand by weight of rice-grain. The second "vitamine" recognized is the anti-rachitic factor (studied by Hopkins), which tends to promote growth and prevent "rickets" in young animals. Certain fats of animal origin (milk) and green leaves contain it in minute quantity, and are necessary for the life of young animals and for the health of adults.

The third vitamine recognized is the anti-scorbutic, the factor which prevents scurvy. It is found in fresh vegetable tissues, and to a less extent in fresh animal tissues. Its richest sources are cabbage, swedes, turnips, lettuce, water-cress, and such fruits as lemons, oranges, raspberries, and tomatoes; other vegetables have a less value. Fresh milk and meat possess a definite but low anti-scorbutic value. This vitamine (I am quoting the report of the Committee, which has been issued to our military, naval, and medical administrators and famine-relief-workers throughout the world) suffers destruction when the fresh food-stuffs containing it are subjected to heat, or drying, as methods of preservation. It is habitually destroyed and wasted by stewing fresh vegetables with meat for two or three hours. All dry food-stuffs, such as cereals, pulses, dried vegetables and dried milk, are deficient in anti-scorbutic properties; so also are tinned vegetables and tinned meat—hence the disgust to which they soon give rise!

The explanation of the mystery about lime-juice (which a hundred years ago was used with absolute success to prevent scurvy, and in 1875 was a dead failure) is shown by the workers at the Lister Institute to be this—namely, "lime" and "lemon" are in origin the same word, and have become applied in ways unrecognized by the Admiralty and their medical advisers in various parts of the world to which the citron, the lemon, the sweet-lime and the sour-lime—all varieties of one species, Citrus medica of Linnæus—have been carried from their original home of origin, the south-east of Asia. The original effective and valuable "lime-juice" of the eighteenth century was lemon-juice, carefully prepared from lemons in Sicily and Italy, and from 1804 to 1860 in Malta. When the demand for it increased in the nineteenth century, it was adulterated and made up from poor fruit, as the commercial enterprise of contractors and the fatuous incapacity of the naval authorities progressed hand in hand. And then, in the early fifties, the West Indian growers of the small sour-lime (Citrus medica var. acida) in Montserrat got the naval contracts, the honest intention of Sir William Burnett, the chief medical officer of the Navy, being to establish a permanent and first-rate supply. Strangely enough, the naval "lime-juice" now really was lime-juice and no longer lemon-juice. By a natural but fatal misconception, the medical value of the juice, whether of lemon or of lime, was by all authorities attributed to the citric acid present; and the only tests applied to it were chemical ones, and not therapeutic. The Lister Institute Committee have shown by therapeutic experiment—the feeding of guinea-pigs, in which scurvy can be produced and cured at will—that the anti-scorbutic vitamine remains active and unimpaired in lemon-juice from which all the citric acid has been extracted. And, further, that the juice of the West Indian sour-lime (Citrus medica acida), although very rich in citric acid, contains only one-fourth the anti-scorbutic vitamine which the same quantity of the juice of the true lemon (Citrus medica limonum) contains. This has been most carefully established by prolonged series of feeding experiments. It explains the failure of the lime-juice in Sir George Nares' Polar Expedition, and restores the confidence in lemon-juice based on the unanimous testimony of the early records of its use.

Whilst lemon-juice is thus justified, Dr. Harriette Chick has made a discovery which will go far to remove it from supremacy. She finds that an anti-scorbutic food can be prepared, when fresh vegetables or fruit are scarce, by moistening any available seeds (wheat, barley, rye, peas, beans, lentils) and allowing them to germinate. This sprouted material possesses an anti-scorbutic value equal to that of many fresh vegetables; the unsprouted seeds have none. Probably this explains the anti-scorbutic value of sweet-wort and of beers made from lightly dried malt; and the total failure in this respect of our modern beers made from kiln-dried malt. Dr. Chick, amongst many other interesting and important results published by members of the Lister Institute Committee, states that the juice of raw swedes and of raw turnips is a valuable anti-scorbutic (to be added to milk for the use of artificially nourished infants); so, she states, is orange-juice. But, contrary to the usual opinion, she finds that beetroot has little or no anti-scorbutic value. The whole subject is of extreme importance, and is necessarily in a tentative stage of pioneer experiment.

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