no difficulty in condensing the volatilized sulphuric acid, which can be used over again. This process is easier, on a laboratory-scale, than the soda carbonate method, which is about as follows: Bauxite is fused with carbonate of soda in a reverberatory furnace. The fused mass is lixiviated with water, which dissolves aluminate of soda, which is decanted off. The solution of aluminate of soda is decomposed by carbonic acid gas, which forms carbonate of soda, which remains in solution, and the alumina hydrate is precipitated. This alumina hydrate is afterwards washed repeatedly with water, dried, and calcined at a red-heat for a considerable time, anhydrous alumina being the result. UINTAITE, ALBERTITE, GRAHAMITE, AND ASPHALTUM DESCRIBED AND COMPARED, WITH OBSERVATIONS ON BITUMEN AND ITS COMPOUNDS. BY WM. P. BLAKE, NEW HAVEN, CONN. (Washington Meeting, February, 1890.) I HAVE not before had the honor of offering to the Institute a communication on the subject of the variety of asphaltum which I described as uintahite; but several disconnected notices of it have appeared in the Transactions, and much additional information regarding it and its relations to other varieties of the asphalt group has been gathered together. Dr. Henry Wurtz has also discussed the nature of uintaite, and has endeavored to show that it should be considered a variety of grahamite.* We have also had an interesting paper upon "Asphalt and its Uses," from Captain F. V. Greene,† containing much important technical information and a scheme of classification of the varieties of bitumen and of bituminous compounds. The object of the present paper is to bring the substance of these disconnected notices together; to present some additional facts; to revise the name uintahite; to compare the substance with the allied bitumens or asphalts, known as albertite and grahamite; and fur * Engineering and Mining Journal, August 10, 1889, xlviii., 114. ther to give a general view of the classification and nomenclature of this class of bodies. Historians record the use of asphalt in the most ancient structures of which we have any knowledge. The Babylonians used it as a cementing substance for their bricks, and according to Brongniart applied it hot. The cradle of the Babylonian Moses was cemented with it. Xenophon, four hundred years before Christ, describes the wall of Media as built of burnt bricks laid in asphalt.* The Scriptures record the use of bitumen in the building of the ark and in the construction of the tower of Babel. The Latin word asphaltum is believed to be derived from the Greek word Acgaros, asphaltos, which in turn is considered to be of Phoenician origin. It was used by Homer, and probably in its Latin form gave the name Asphaltites to the lake in Palestine, now known as the Dead Sea, and anciently as the source of bitumen, called bitumen judaicum. Pliny describes this bitumen, which he says at certain seasons of the year is found floating upon Lake Asphaltites, as a "substance which is peculiarly tenacious and adheres to everything it touches."+ In the more formal description he considers it as nearly approaching the nature of sulphur, which in some places assumes the form of slime and in others that of an earth. He also describes, under the name of maltha, an inflammable mud from the Euphrates.§ This name, which has been generally given to the soft viscid and semifluid bitumens, is derived, according to Dana, from the Greek word meaning soft wax, and sometimes a mixture of wax and pitch. Pliny also used the word pissasphaltus, derived from açaros (Dioscorides i), meaning pitch-asphalt. Hill, the translator, in the last century, of Theophrastus's "History of Stones," thinks that this ancient writer, the pupil of Aristotle, about three hundred years before Christ, referred to asphaltum when he described certain "brittle stones," as he terms them, which became, "as it were, burning coals when put into a fire and emitted, troublesome and disagreeable smell." This description would, however, refer equally well, or better, to coal, and is so applied by Dana. It will be noted that Pliny describes the bitumen of the Dead Sea as a viscous body, and in another part of his Natural History * Anabasis, Book II., iv., 12. † Natural History, Book vii., 13. || Dana's Mineralogy, 5th edit., 728. Book XXXV., & 51. ? Book II., 108. ¶ History of Stones, Section XXIII., and notes by Hill. he describes how it may be cut asunder by a string if dipped in a peculiar bloody menstruum. In contrast with this idea of a viscid body the following is from Bergman, of Sweden, who, in 1784, gave an interesting description of bitumen. He said: "The asphalte, or bitumen of Judea, so named because it is found upon the waters of the Lake Asphaltide, in Judea, is a bitumen, solid, black, brittle, brilliant in its fracture, which is vitreous; its black color is really a brownish red, since a thin flake held between the eye and the light appears red. It floats upon water, and in the fire it burns, giving off the odor of amber. When it is very pure it burns with a clear flame without leaving any residue; when impure, it leaves carbon or a scoria."* This description is more nearly in accord with the characters of pure solid asphalt than any other I have found in the writings of the mineralogists of the last century. Bergman also describes naphtha, petroleum, maltha and pissasphalte as examples of the gradation of the fluid bitumen into the solid forms of asphalt and of jet, this last being regarded by him as only a more solid bitumen. He also made a distinction between these bituminous substances and bitumen in combination with earthy substances. Le Sage, in 1777,† had given nearly the same classification of bitumens, placing in sequence, naphtha, petroleum, mineral pitch, maltha and asphalt, or bitumen of Judea, and regarded them all as originating from fluid petroleum. He quotes Wallerius to the same effect. Wallerius, in 1778, grouped the bitumens under the general head of "Inflammable Substances," placing them in the following order: bitumen, naphtha, petroleum, maltha, asphalte, bituminous earth, stone-coal, jet. Woltersdorff, 1748, under the head of " Bitumens," made two classes—the fluid and the solid-placing petroleum in the first, and amber, succin, mountain pitch and sulphur in the second. Brongniart, in 1807, under the heading of "Bitumen," credited to Haüy, wrote: "Les variétés de cette espèce sont la plupart peu distinctes et passent de l'une à l'autre par des nuances insensibles."§ * Manuel du Minéralogiste ou Sciagraphie du Règne Minéral. Par M. Torbern Bergman. Traduite et augmentée de notes par M. Mongez. Paris, MDCCLXXXIV. + Le Sage, Élémens de Minéralogie, i., 101-103. 1777. Elucet asphaltum nihil aliud esse quam vel petroleum coagulum vel maltham inspissatam.-System. Minéralogie, ii., 96. ¿ Traité Élémentaire de Minéralogie, ii., 19--29. These varieties are there described in the following order: naphtha, petroleum, maltha, asphalte. These views of the derivation of this group of hydrocarbons have been followed by most mineralogical writers of this century. Boussingault, in 1837,* made a special investigation of the composition of asphalt, taking the viscid bitumen of Bechelbronn for his experiments. He found it only slightly acted on by alcohol; the liquid assuming a yellow color when aided by heat, but in sulphuric ether it was easily dissolved. At a temperature of 230° C., in an oil-bath, he separated an oily liquid to which he gave the name pétrolène, regarding it as the liquid constituent of bitumens, which, mingled in varying quantities with a solid substance, asphaltine, forms the bitumens of different degrees of fluidity. He describes asphaltene as brilliant black in color and luster, with a conchoidal fracture, and heavier than water. Towards a temperature of 300° C., it becomes soft and elastic. It begins to decompose before it melts, and burns like the resins, leaving an abundance of coke. Boussingault takes the asphalte of Caxitambo, Peru, first brought into notice by Humboldt, as a type of the asphalts, and describes it as having such a large conchoidal fracture and such a brilliant luster and black color that it might be supposed to be obsidian. It has a specific gravity of 1.68. It is difficult to dissolve in petrolene or in the thick oils. In further support of the opinion of the mixture of the two substances, petrolene and asphaltene, Boussingault says that it is always possible to thicken a soft bitumen by volatilizing the liquid portion by heat. This is done by the Indians of Payta to gain the consistence of bitumen needed for paying their boats. Dr. T. Sterry Hunt, in 1862, regarded the bitumens and asphalts as intermediate links in the series of substances between solid coal and fluid petroleum. He says: "Anthracite, or nearly pure carbon, on the one hand, and petroleum, or carbon with a maximum of hydrogen on the other, represent the two extremes of the process of which bituminous coals and asphalts are intermediate terms." And in regard to their origin or formation, he says: "Although we have seen that the solid asphalts, which differ from petroleum in containing less hydrogen and a portion of oxygen, have in most cases been directly formed from organic matters by a process analogous to that which yields coal and petroleum ; it appears that the latter body, like other hydrocarbons, may gradually undergo an * Ann. de Ch. et de Phys. (II.), lxiv., p. 141–151. oxidizing process, which by removing hydrogen and adding oxygen, at last converts the liquid into substances having the characters of asphalt, of coal, or even of anthracite." In describing further the occurrence of hard, black, brittle hydrocarbons in fissures of rocks of the Quebec group in Canada, he says: "The mode of occurrence of these matters shows that they have once been in a liquid state, and, as the limestones of this group are in many parts distinctly bituminous, there can be little doubt that the liquid carbonaceous matter was bitumen which has since been slowly oxidized, indurated and converted into these insoluble, infusible coaly and anthracitic bodies."* Daubrée, writing in 1868,† said that we might include under the general name of bitumens, carbonaceous bodies of varied nature, from petroleum to viscous bitumen, or maltha; sometimes, also, called pissasphalte; and even include that which is solid at ordinary temperatures, to which the name asphalt is reserved. Beckwith's description of bitumen (asphalt) is as follows: From whatever source derived, superior bitumen exhibits the following properties: Its color is brilliant black with a reddish tinge. The reddish tinge augments when bitumen is softened and drawn into threads. The fracture is conchoidal at a low temperature. Below 50° (F.) it is solid and brittle; from 50° to 70° it is elastic and begins to soften; from 70° to 90° it becomes soft and pasty; from 90° to 100° viscous; and at 110° or 120° it melts. Its specific gravity is 1.025. The odor is empyreumatic and free from the noxious smell of coal-tar. The more modern and comparatively recent attempts at a scientific classification of the bitumens and hydrocarbons generally are based upon their chemical composition. Thus Prof. Dana in the fifth edition of his Mineralogy places the hydrocarbons in five groups: 1. Simple; 2. Oxygenated; 3. Acid oxygenated; 4. Salts of organic acids; 5. Nitrogenous; but is obliged to place asphaltum and mineral coal in an appendix to the series. I now pass to a consideration of the three substances which, under the names of albertite, grahamite, and uintaite, are generally known, and may be considered as the best examples we now have of pure asphalt on a large scale. In regard to albertite, however, * Contributions to the Chemical and Geological History of Bitumens and of Pyroschists, by T. Sterry Hunt, M.A., F.R.S., American Journal of Science [II.], xxxv., 164, March, 1863. † Substances Minérales. |