Earth-oil creek in Burma. Barbados tar. Galician oil. St. Quiri nus's oil. Bitumen at time. This oil," he adds, "is not good to use with food, but is good to burn, and is also used to anoint camels that have the mange." The oil springs of Persia, and the renowned petroleum wells of Yenangyaung (earth-oil creek) in Burma, have been often described by travellers, and it was from the asphalt of Trinidad that Gesner first prepared kerosene. The crude petroleum of Barbados, imported under the name of Barbados tar, formerly occupied a place of some importance in the Materia Medica of this and other countries. It was thus referred to in 1750 by Griffith Hughes in his "Natural History of the Island of Barbados": "The most remarkable fossil of bituminous kind is green tar. It is obtained by digging holes or a trench, and it rises on the water. It issues from hills, and is gathered in the months of January, February and March, and serves to burn in lamps." Historical records show that from very early times crude petroleum has been collected in Austria-Hungary for use as cart-grease, and the Alstetterring, in Prague, is said to have been lighted by oil distilled from petroleum obtained in Galicia as far back as 1810, or between that date and 1818. In 1436, petroleum from the Tegern See in Bavaria was sold under the name of St. Quirinus's oil as a medicinal agent, and in Italy a concession was granted in the year 1400 for the collection of petroleum from wells at Miano. The petroleum of Modena, which at one time was largely used for lighting and medicinal purposes, as well as in the preparation of varnishes and paints, was discovered by Ariosto, a physician of Ferrara, in 1640. The following interesting account of the occurrence Pitchford, of bitumen at Pitchford in Shropshire is taken from Camden's "Britannia": Shropshire. "A little village call'd Pitchford, which formerly gave name to the ancient family of the Pitchfords, is now the possession of the Otelies. Our ancestors gave it the name of Pitchford from a spring of pitchy water; for in those days, they knew no distinction between pitch and bitumen. And here is a well in a poor man's yard, upon which there floats a sort of liquid bitumen, although it be every day scummed off; after the same manner as it doth on the lake Asphaltites in Judæa, and on a standing pool about Samosata, and on a spring by Agrigentum in Sicily; but the inhabitants make no other use of it than as pitch. Whether it be a preservative against the Falling-sickness, or be good for drawing and healing of wounds (as that in Judæa is), I know no one yet that has made the experiment. Here, and in the adjacent places, there lies over most of the Coal-pits or Mines, a Stratum or layer of blackish rock, of which, by grinding and boiling, they make pitch and tar, and from which also a kind of Oil is distill'd." Derbyshire. There are many other places in Great Britain where Oil spring in petroleum occurs in small quantities, and it is worthy of note that James Young, the founder of the Scottish shale oil industry, commercially utilised a spring of petroleum which had been met with in the workings of the Riddings Colliery at Alfreton, in Derbyshire, before he took out his celebrated patent for obtaining "paraffine oil or an oil containing paraffine, and paraffine from bituminous coals." The Origin of Petroleum. It is not surprising that a natural product of so distinctive and, one may add, of so self-assertive a character should have attracted the attention of men of science, and we find in some of the earlier treatises amusing statements in reference to the nature and origin of petroleum. Bacon Early in his Sylva Sylvarum tells us that the original con theories. Modern theories. cretion of bitumen is a mixture of a fiery and watery substance, and remarks that flame attracts the naphtha of Babylon afar off. Macquer published in 1764 a treatise on chemistry in which bitumen is defined as a mineral substance yielding petroleum on distillation, and as an oil rendered consistent and solid by being combined with an alkali, but in the same work bitumen is described as belonging as much to the vegetable as to the mineral kingdom; the author further states that solid bitumen appears to be a vegetable oil combined with a mineral acid, and expresses the opinion that bitumens are the resinous and oily parts of trees or plants. Bergmann in his "Physical and Chemical Essays," which appeared during the years 1788-1791, expressed the view that petroleum was an example of a small proportion of water combined by means of an acid with the principle of inflammability. Amongst the earlier writers on the subject none contributed more specific and correct information than Hatchett, whose views will be found in the Transactions of the Linnean Society for 1798. It was, he said, generally admitted at that time that bituminous substances are not of mineral origin, "but have been formed from certain principles of substances belonging to the organised kingdoms of nature." He further specified the elementary principles (as he called them) of bitumen as carbon, hydrogen, sometimes azote and probably some oxygen, a remarkably correct definition, by the way, and from the correspondence between this composition and that of the vegetable and animal oils and resins he arrives at the conclusion that metamorphic action has produced petroleum from these sources. The latter half of the past century has been fertile in theories of the origin of petroleum, and many eminent men have devoted much thought to the subject. The various modern theories may be broadly classified into two groups, one consisting of those which assign to the product an inorganic origin, and the other those which account for its production from animal or vegetable matter, or both. Berthelot's The first exponent of the theory of inorganic origin Inorganic was the distinguished chemist Berthelot, who, proceed- origin. ing upon the hypothesis of Daubrée that free alkali- experimetals exist in the interior of the earth, ascertained ments. experimentally that when carbonic acid or an earthy carbonate acts upon the alkali-metals at a high temperature, acetylides are formed, and that these bodies when acted upon by water-vapour, under the conditions prevailing in the earth, yield hydrocarbons resembling those of American petroleum, the precise composition of the hydrocarbons varying with the temperature. He therefore in 1866 expressed the view that petroleum may have been produced by the infiltration of water containing carbonic acid into the interior of the earth, where it would be brought into contact with the alkali metals at an elevated temperature. Many years later Maquenne prepared acetylide or carbide of barium (C,Ba) and obtained acetylene by its action on water, and still more recently through the discovery of Willson, one of the carbides, viz., that of calcium, has become an ordinary article of commerce, and acetylene a common illuminating agent. Of still Researches greater interest, however, in connection with the of Moissan. subject we are considering, have been the results of the work of Moissan, who has found that certain of the carbides yield liquid hydrocarbons on decomposition with water. In a paper published in the Journal of the American Chemical Society in 1899, Mr. J. A. Matthews has given the following classification of the reactions of decomposition of the carbides : (1) The carbides of lithium, sodium, potassium, Byasson's theory. view. calcium, barium and strontium are decomposed by water, giving mostly acetylene. (2) Silver, copper, mercury and gold (?) acetylides are acted on by hydrochloric acid, giving acetylene. (3) Aluminium and beryllium carbides react with water, yielding methane. (4) Manganese carbide with water gives methane and hydrogen. (5) The carbides of yttrium, lanthanum and thorium are decomposed by water, giving mixtures of acetylene, ethylene, methane and hydrogen. (6) Lanthanum, cerium and uranium carbides give with water, besides the volatile products, a residue of liquid and solid hydrocarbons. It will thus be seen that several of the carbides, including that of manganese, yield methane (CH4), the lowest member of the paraffins present in Pennsylvania petroleum, and that some actually yield liquid and solid hydrocarbons. In 1871, Byasson, in a memoir on the origin of petroleum published in Paris, suggested that petroleum might have resulted from the action on iron or sulphide of iron at a white heat, of steam and carbonic acid gas, resulting from the infiltration of salt water to great depths in the earth, his theory, like that of Berthelot, being based upon laboratory experiments in which petroleum was obtained. In 1877 Cloez obtained petroleum-like hydrocarbons by the action of dilute mineral acid or even boiling water on a spiegeleisen (carbide of iron and manganese), Mendeleeff's and the eminent Russian chemist Mendeleeff gave the weight of his authority to the view that petroleum is of inorganic origin. The great density of the earth, and the well-known presence of iron in meteorites, in the solar system (as shown by the spectroscope), and in eruptive rocks, are regarded by Mendeleeff as |