Volume 2, Slice 2 Part 15 (1/2)
Formerly, anthracite was largely used, both in America and South Wales, as blast-furnace fuel for iron smelting, but for this purpose it has been largely superseded by c.o.ke in the former country and entirely in the latter. An important application has, however, been developed in the extended use of internal combustion motors driven by the so-called ”mixed,” ”poor,” ”semi-water” or ”Dowson gas” produced by the gasification of anthracite with air and a small proportion of steam.
This is probably the most economical method of obtaining power known; with an engine as small as 15 horse-power the expenditure of fuel is at the rate of only 1 lb per horse-power hour, and with larger engines it is proportionately less. Large quant.i.ties of anthracite for power purposes are now exported from South Wales to France, Switzerland and parts of Germany. (H. B.)
ANTHRACOTHERIUM (”coal-animal,” so called from the fact of the remains first described having been obtained from the Tertiary lignite-beds of Europe), a genus of extinct artiodactyle ungulate mammals, characterized by having 44 teeth, with five semi-crescentic cusps on the crowns of the upper molars. In many respects, especially the form of the lower jaw, _Anthracotherium_, which is of Oligocene and Miocene age in Europe, and typifies the family _Anthracotheriidae_, is allied to the hippopotamus, of which it is probably an ancestral form. The European _A. magnum_ was as large as the last-mentioned animal, but there were several smaller species and the genus also occurs in Egypt, India and North America.
(See ARTIODACTYLA.)
ANTHRAQUINONE, C14H8O2, an important derivative of anthracene, first prepared in 1834 by A. Laurent. It is prepared commercially from anthracene by stirring a sludge of anthracene and water in horizontal cylinders with a mixture of sodium b.i.+.c.hromate and caustic soda. This suspension is then run through a conical mill in order to remove all grit, the cones of the mill fitting so tightly that water cannot pa.s.s through unless the mill is running; the speed of the mill when working is about 3000 revolutions per minute. After this treatment, the mixture is run into lead-lined vats and treated with sulphuric acid, steam is blown through the mixture in order to bring it to the boil, and the anthracene is rapidly oxidized to anthraquinone. When the oxidation is complete, the anthraquinone is separated in a filter press, washed and heated to 120 C. with commercial oil of vitriol, using about 2 parts of vitriol to 1 of anthraquinone. It is then removed to lead-lined tanks and again washed with water and dried; the product obtained contains about 95% of anthraquinone. It may be purified by sublimation. Various synthetic processes have been used for the preparation of anthraquinone.
A. Behr and W.A. v. Dorp (_Ber._, 1874, 7, p. 578) obtained orthobenzoyl benzoic acid by heating phthalic anhydride with benzene in the presence of aluminium chloride. This compound on heating with phosphoric anhydride loses water and yields anthraquinone,
/CO C6H6 /COC6H6 /CO C6H4<>O -> C6H4< -=””> C6H4<>C6H4.
CO/ COOH CO/
It may be prepared in a similar manner by heating phthalyl chloride with benzene in the presence of aluminium chloride. Dioxy- and tetraoxy-anthraquinones are obtained when meta-oxy- and dimeta-dioxy-benzoic acids are heated with concentrated sulphuric acid.
Anthraquinone crystallizes in yellow needles or prisms, which melt at 277 C. It is soluble in hot benzene, sublimes easily, and is very stable towards oxidizing agents. On the other hand, it is readily attacked by reducing agents. With zinc dust in presence of caustic soda it yields the secondary alcohol oxan-thranol, C6H4 : COCHOH : C6H4, with tin and hydrochloric acid, the phenolic compound anthranol, C6H4 : COC(OH) : C6H4; and with hydriodic acid at 150 C. or on distillation with zinc dust, the hydrocarbon anthracene, C14H10. When fused with caustic potash, it gives benzoic acid. It behaves more as a ketone than as a quinone, since with hydroxylamine it yields an oxime, and on reduction with zinc dust and caustic soda it yields a secondary alcohol, whilst it cannot be reduced by means of sulphurous acid. Various sulphonic acids of anthraquinone are known, as well as oxy-derivatives, for the preparation and properties of which see ALIZARIN.
ANTHRAX (the Greek for ”coal,” or ”carbuncle,” so called by the ancients because they regarded it as burning like coal; cf. the French equivalent _charbon_; also known as _fievre charbonneuse, Milzbrand_, splenic fever, and malignant pustule), an acute, specific, infectious, virulent disease, caused by the _Bacillus anthracis_, in animals, chiefly cattle, sheep and horses, and frequently occurring in workers in the wool or hair, as well as in those handling the hides or carcases, of beasts which have been affected.
_Animals._--As affecting wild as well as domesticated animals and man, anthrax has been widely diffused in one or more of its forms, over the surface of the globe. It at times decimates the reindeer herds in Lapland and the Polar regions, and is only too well known in the tropics and in temperate lat.i.tudes. It has been observed and described in Russia, Siberia, Central Asia, China, Cochin-China, Egypt, West Indies, Peru, Paraguay, Brazil, Mexico, and other parts of North and South America, in Australia, and on different parts of the African continent, while for other European countries the writings which have been published with regard to its nature, its peculiar characteristics, and the injury it inflicts are innumerable. Countries in which are extensive marshes, or the subsoil of which is tenacious or impermeable, are usually those most frequently and seriously visited. Thus there have been regions notorious for its prevalence, such as the marshes of Sologne, Dombes and Bresse in France; certain parts of Germany, Hungary and Poland; in Spain the half-submerged valleys and the maritime coasts of Catalonia, as well as the Romagna and other marshy districts of Italy; while it is epizootic, and even panzootic, in the swampy regions of Esthonia, Livonia, Courland, and especially of Siberia, where it is known as the _Sibirskaja jaswa_ (Siberian boil-plague). The records of anthrax go back to a very ancient date. It is supposed to be the murrain of Exodus. Cla.s.sical writers allude to anthrax as if it were the only cattle disease worthy of mention (see Virgil, _Georg._ iii.). It figures largely in the history of the early and middle ages as a devastating pestilence attacking animals, and through them mankind; the oldest Anglo-Saxon ma.n.u.scripts contain many fantastic recipes, leechdoms, charms and incantations for the prevention or cure of the ”blacan blezene” (black blain) and the relief of the ”elfshot” creatures. In the 18th and 19th centuries it sometimes spread like an epizootic over the whole of Europe, from Siberia to France. It was in this malady that disease-producing germs (_bacteria_) were first discovered, in 1840, by Pollender of Wipperfurth, and, independently, by veterinary surgeon Brauell of Dorpat, and their real character afterwards verified by C.J.
Davaine (1812-1882) of Alfort in 1863; and it was in their experiments with this disease that Toussaint, Pasteur and J.B. Chauveau first showed how to make the morbific poison its own antidote. (See VIVISECTION.)
The symptoms vary with the species of animal, the mode of infection, and the seat of the primary lesion, internal or external. In all its forms anthrax is an inoculable disease, transmission being surely and promptly effected by this means, and it may be conveyed to nearly all animals by inoculation of a wound of the skin or through the digestive organs.
Cattle, sheep and horses nearly always owe their infection to spores or bacilli ingested with their food or water, and pigs usually contract the disease by eating the flesh of animals dead of anthrax.
Internal anthrax, of cattle and sheep, exhibits no premonitory symptoms that can be relied on. Generally the first indication of an outbreak is the sudden death of one or more of the herd or flock. Animals which do not die at once may be noticed to stagger and tremble; the breathing becomes hurried and the pulse very rapid, while the heart beats violently; the internal temperature of the body is high, 104 to 106 F.; blood oozes from the nose, mouth and a.n.u.s, the visible mucous membranes are dusky or almost black. The animal becomes weak and listless, the temperature falls and death supervenes in a few hours, being immediately preceded by delirium, convulsions or coma. While death is usually rapid or sudden when the malady is general, const.i.tuting what is designated splenic apoplexy, internal anthrax in cattle is not invariably fatal. In some cases the animal rallies from a first attack and gradually recovers.
In the external or localized form, marked by the formation of carbuncles before general infection takes place, death may not occur for several days. The carbuncles may appear in any part of the body, being preceded or accompanied by fever. They are developed in the subcutaneous connective tissue where this is loose and plentiful, in the interstices of the muscles, lymphatic glands, in the mucous membranes of the mouth and tongue (glossanthrax of cattle), pharynx and larynx (_anthrax angina_ of horses and pigs), and the r.e.c.t.u.m. They begin as small circ.u.mscribed swellings which are warm, slightly painful and oedematous.
In from two to eight hours they attain a considerable size, are cold, painless and gangrenous, and when they are incised a quant.i.ty of a blood-stained gelatinous exudate escapes. When the swellings have attained certain proportions symptoms of general infection appear, and, running their course with great rapidity, cause death in a few hours.
Anthrax of the horse usually begins as an affection of the throat or bowel. In the former there is rapid obstructive oedema of the mucous membrane of the pharynx and larynx with swelling of the throat and neck, fever, salivation, difficulty in swallowing, noisy breathing, frothy discharge from the nose and threatening suffocation. General invasion soon ensues, and the horse may die in from four to sixteen hours. The intestinal form is marked by high temperature, great prostration, small thready pulse, tumultuous action of the heart, laboured breathing and symptoms of abdominal pain with straining and diarrhoea. When moved the horse staggers and trembles. Profuse sweating, a falling temperature and cyanotic mucous membranes indicate the approach of a fatal termination.
In splenic fever or splenic apoplexy, the most marked alterations observed after death are--the effects of rapid decomposition, evidenced by the foul odour, disengagement of gas beneath the skin and in the tissues and cavities of the body, yellow or yellowish-red gelatinous exudation into and between the muscles, effusion of citron or rust-coloured fluid in various cavities, extravasations of blood and local congestions throughout the body, the blood in the vessels generally being very dark and tar-like. The most notable feature, however, in the majority of cases is the enormous enlargement of the spleen, which is engorged with blood to such an extent that it often ruptures, while its tissue is changed into a violet or black fluid ma.s.s.
The bacillus of anthrax, under certain conditions, retains its vitality for a long time, and rapidly grows when it finds a suitable field in which to develop, its mode of multiplication being by scission and the formation of spores, and depending, to a great extent at least, on the presence of oxygen. The morbid action of the bacillus is indeed said to be due to its affinity for oxygen; by depriving the red corpuscles of the blood of that most essential gas, it renders the vital fluid unfit to sustain life. Albert Hoffa and others a.s.sert that the fatal lesions are produced by the poisonous action of the toxins formed by the bacilli and not by the blocking up of the minute blood-vessels, or the abstraction of oxygen from the blood by the bacilli.
It was by the cultivation of this micro-organism, or attenuation of the virus, that Pasteur was enabled to produce a prophylactic remedy for anthrax. His discovery was first made with regard to the cholera of fowls, a most destructive disorder which annually carries off great numbers of poultry. Pasteur produced his inoculation material by the cultivation of the bacilli at a temperature of 42 C. in oxygen. Two vaccines are required. The first or weak vaccine is obtained by incubating a bouillon culture for twenty-four days at 42 C., and the second or less attenuated vaccine by incubating a bouillon culture, at the same temperature, for twelve days. Pasteur's method of protective inoculation comprises two inoculations with an interval of twelve days between them. Immunity, established in about fifteen days after the injection of the second vaccine, lasts from nine months to a year.
Toussaint had, previous to Pasteur, attenuated the virus of anthrax by the action of heat; and Chauveau subsequently corroborated by numerous experiments the value of Toussaint's method, demonstrating that, according to the degree of heat to which the virus is subjected, so is its inocuousness when transferred to a healthy creature. In outbreaks of anthrax on farms where many animals are exposed to infection immediate temporary protection can be conferred by the injection of anthrax serum.
_Human Beings._--For many years cases of sudden death had been observed to occur from time to time among healthy men engaged in woollen manufactories, particularly in the work of sorting or combing wool. In some instances death appeared to be due to the direct inoculation of some poisonous material into the body, for a form of malignant pustule was observed upon the skin; but, on the other hand, in not a few cases without any external manifestation, symptoms of blood-poisoning, often proving rapidly fatal, suggested the probability of other channels for the introduction of the disease. In 1880 the occurrence of several such cases among woolsorters at Bradford, reported by Dr J.H. Bell of that town, led to an official inquiry in England by the Local Government Board, and an elaborate investigation into the pathology of what was then called ”woolsorters' disease” was at the same time conducted at the Brown Inst.i.tution, London, by Professor W.S. Greenfield. Among the results of this inquiry it was ascertained: (1) that the disease appeared to be identical with that occurring among sheep and cattle; (2) that in the blood and tissues of the body was found in abundance, as in the disease in animals, the _Bacillus anthracis_, and (3) that the skins, hair, wool, &c., of animals dying of anthrax retain this infecting organism, which, under certain conditions, finds ready access to the bodies of the workers.
Two well-marked forms of this disease in man are recognized, ”external anthrax” and ”internal anthrax.” In external anthrax the infecting agent is accidentally inoculated into some portion of skin, the seat of a slight abrasion, often the hand, arm or face. A minute swelling soon appears at the part, and develops into a vesicle containing serum or b.l.o.o.d.y matter, and varying in size, but seldom larger than a s.h.i.+lling.
This vesicle speedily bursts and leaves an ulcerated or sloughing surface, round about which are numerous smaller vesicles which undergo similar changes, and the whole affected part becomes hard and tender, while the surrounding surface partic.i.p.ates in the inflammatory action, and the neighbouring lymphatic glands are also inflamed. This condition, termed ”malignant pustule,” is frequently accompanied with severe const.i.tutional disturbance, in the form of fever, delirium, perspirations, together with great prostration and a tendency to death from septicaemia, although on the other hand recovery is not uncommon.
It was repeatedly found that the matter taken from the vesicle during the progress of the disease, as well as the blood in the body after death, contained the _Bacillus anthracis_, and when inoculated into small animals produced rapid death, with all the symptoms and post-mortem appearances characteristic of che disease as known to affect them.
In internal anthrax there is no visible local manifestation of the disease, and the spores or bacilli appear to gain access to the system from the air charged with them, as in rooms where the contaminated wool or hair is unpacked, or again during the process of sorting. The symptoms usually observed are those of rapid physical prostration, with a small pulse, somewhat lowered temperature (rarely fever), and quickened breathing. Examination of the chest reveals inflammation of the lungs and pleura. In some cases death takes place by collapse in less than one day, while in others the fatal issue is postponed for three or four days, and is preceded by symptoms of blood-poisoning, including rigors, perspirations, extreme exhaustion, &c. In some cases of internal anthrax the symptoms are more intestinal than pulmonary, and consist in severe exhausting diarrhoea, with vomiting and rapid sinking.