Christianity is yielding to a more humane if less imposing creed. Our duty, then, is unmistakable. We may not preach a sensual or earthly doctrine, as neither do we need; but preach we must that the beginning of the kingdom of heaven is here and now. Redemption from sin brings with it social regeneration; for mankind, as for the individual, there are sacraments of healing. We have long taught that "One is our Father in Heaven;" it is required now to prove by every means in our power that men are brethren. Point by point we must take the Socialist doctrine, which assumes to start from this very principle, and show that its conception of man's brotherhood, however like in terms to that of the Gospel, is diametrically the opposite, because it does not recognize the deepest foundation of our nature, which is spiritual. The same Gospel which condemns inhuman greed of wealth, teaches us that we cannot live by bread alone. But the supreme social duty is justice, apart from which neither rich nor poor can be what they ought to be, servants of the Eternal.

"What is justice? That, on the whole, is the question of the Sphinx for us." The Gospel does not enter into infinite detail; but surely, even now, in a time when "men and nations perish as if without law," it is possible for Christian teachers, thinking steadily over the matter, to deliver righteous judgments on the problems under which we stagger. This, I say, it is our bounden duty to attempt. We have no message to the thirteenth or the sixteenth centuries, now gone before God with all their imperfections on them. Our message is to our own day or to no day. We cannot pretend that it may be learnt by merely opening the Bible, quoting the Fathers and Doctors, or uttering by rote what is affirmed in schools of theology. A living doctrine reveals itself only to a living spirit which is constantly engaged in translating the dead words of the past into such language as men will understand. What is more, the grander that past, the larger the inheritance it has bequeathed us, so much the more likely are we to sit down contented with the thought that it is all there, and we need trouble no further to make it ours. Between possessing the faith and comprehending it lies the whole immense difference which divides the implicit from the explicit, or, in plainer terms, the acorn from the oak under whose wide-spreading leafy branches a host may find shelter. There are in the Christian social doctrine a multitude of unfolded germs, waiting to be tended and made to yield their increase. Religion has raised up the saints who devised and propagated Monasticism; the saints who consecrated to Christian uses Greek philosophy and Latin literature; the șaints who sent out missionary orders all over the world. At this day we are sorely in need of loyal and devoted spirits, filled

with enthusiastic love for the brethren, who shall discern the signs of the times, and help to make that new social order which is surely coming "the kingdom of God and His Christ." It will not resemble the state of things we have hitherto known; it can be founded neither on slavery nor on a prolétariat crowded into unwholesome cities, neither on aristocracies that do not work and are wanting in light, nor on military despotism: so much, I think, we may safely affirm. If, as high authorities hold, the law of progress is from status to contract, from fixed hierarchies, where each man abides as he was born, to the largest individual freedom, then it is clear the Gospel principles of justice, charity, and brotherhood will be needed more than ever. Equally clear it is that the problem of their application, becoming so much more complex and delicate, will demand a higher wisdom than politicians as yet have dreamt of. The ultimate purpose of industries, inductive sciences, and the whole machinery of civilization is, we know well, "the glory of God and the relief of man's estate." Socialism, which takes not into account God's glory, can do nothing for man except plunge him into war with his kind till confusion reigns without check. But the Gospel, in revealing a Divine Incarnation, has given us principles which establish the only true social order and union of each with his fellow in wealthy rest. I do not say that words without the "chivalry of labour" will avail much. But yet, again," it is so easy to act, so hard to think." There will go a great deal of strenuous thinking to this task of getting the multitudes imbued with a genuine Christianity, and convincing rich, as well as poor, of sin, and justice, and judgment. It means no less than the second conversion of Europe, and is "work for a god." 1." Yes, truly. But it remains to be done. "The sooty hell of mutiny and savagery and despair can, by man's energy, be made a kind of heaven; cleared of its soot, of its mutiny, of its need to mutiny; the everlasting arch of Heaven's azure overspanning it too, and its cunning mechanisms and tall chimneysteeples, as a birth of Heaven; God and all men looking on it well pleased." This noble vision of the day when science and industry, consecrated to God, shall make an end of Nihilism, is for times, alas! far distant. But there is a Catholic Church in the world; and it will be due to blindness, cowardice, self-indulgence, and disloyalty to their own ideal on the part of Catholics, if, sooner or later, it be not in a measure realized.

WILLIAM BARRY.

ART. III. THE FUTURE OF PETROLEUM.

1. The Region of the Eternal Fire. By CHARLES MARVIN. London: W. H. Allen & Co. 1884.

2. Report by Consul Lovett on the Petroleum Trade of Baku. Parliamentary Papers. 1882.

3. The Petroleum Industries of Europe. By HERBERT TWEDDLE, Jun. Engineering, Jan. 29, 1886 et seq.

4. Petroleum and its Products. By A. NORMAN TATE, F.C.S. London: John W. Davies. 1863.

HE allegories by which popular fancy has in all ages symbo

century translated into sober fact. The dragon-guarded gold of Teutonic fable, the jewel fruits of Aladdin's garden, the Nibelung's shining hoard, the treasure of Morgana's realm, are fetched from the nether world, no longer by gnomes and sorcerers, but by adroit financiers and speculative joint-stock companies. These modern wizards wield spells not less potent than those of the older necromancy, for steam-perforator and dynamite charge are as efficient rock-openers as were ever magic wand or mystic chafing-dish. Nature's subterranean treasure-house still holds the secret of a charm as powerful as that conferred by lamp and ring on the fortunate son of Mustapha the tailor; nor are the genii of the cave less active and zealous now than in those days of yore in ministering to the will of those who have divined the method of their subjugation.

But folk-lore dealt only in such glittering spoil as suggested riches to the eye no less than to the mind, and would have scorned fairy gifts in the unprepossessing form of pitchy oils or petrified charcoal. Yet nature in these latter has conferred boons on man more substantial far than in largesse of dazzling gem or yellow ore, for while the so-called precious stones and metals have a purely adventitious value, the reserve of light and heat stored in the more unpretending mineral deposits is an indispensable auxiliary in the battle of humanity.

Rock-oil and rock-carbon, or petroleum and coal, are in a sense rivals, since they vie in the same field of usefulness; while many contend that the reign of the latter is passing away, and that to the former will fall the chief share in controlling the economic future of the world. Though closely resembling each other in their chemical constituents and products, these two carbon compounds differ essentially in outward and visible characteristics.

Petroleum belongs to the class of substances generally known as bitumens; a group of hydrocarbons varying in density and darkness of colour in the direct degree in which oxygen or products of oxidization enter into their composition. At one end of the scale is solid bitumen, or asphalt, and at the other, naphthaa light and volatile fluid, perfectly limpid or tinted only with pale straw-colour; while intermediate hetween the two, and passing into them by insensible gradations, are maltha, or mineral tar, a dark and pitch-like substance as its name implies, and petroleum found in its natural state in varying degrees of density from that of molasses to that of fine olive-oil. Its hue, which has also many gradations, is due entirely to the intermixture of impurities; its true constituents being absolutely colourless. Among these a large place is filled by paraffin, which derives its name, parum affinis, from its refusal to combine with any other body. Of the distinctive properties of petroleum the most striking is its fluorescence, or capability of rendering visible the ultra-violet rays of light, shown in a blue glare from its surface wherever massed in considerable quantity.

Chemists are at issue as to its origin, for though obviously a product of organic life, it is an open question whether it be due to animal or vegetable decomposition. The actual manufacture of similar oils from the artificial distillation of coal seems to countenance the supposition of its having been derived from a similar process naturally carried on. Its origin is thus referred to the distillation of coal and other bituminous minerals at very low temperatures, and it is asserted that though frequently found remote from coal deposits, carbonaceous shales are always discoverable in its neighbourhood.

Another conjecture seeks its genesis in the decay of woody fibre; a process in which are evolved such volatile hydrocarbons as marsh-gas, parent of the familiar will-o'-the-wisp, and typical of a large class of the constituents of petroleum termed hydrides.

Those who see in it a resultant of animal life base their theory on its occurrence in the lower paleozoic strata, where no traces of land plants exist, and where its formation is supposed to be due to marine organisms. But whatever the process carried on for its elaboration, it is probably still in operation, since a substance, whose lighter constituents are so easily volatilized, could scarcely continue to subsist in the liquid state in situations whence the gases evolved from it frequently find an outlet to the open air. It is, as a rule, thicker and heavier when near the surface, from having undergone partial evaporation, and more fluid when found at greater depths, since it has not there parted with its lighter elements.

In colour it is generally dark-greenish, brown, or nearly black,

from the presence of impurities, eliminated by a protracted process of refining. Exceptionally, however, it is drawn from the well as bright and limpid as the best purified oil. Such a spring exists at Smith's Ferry, Pennsylvania; others in the Caspian region yield naphtha clear and pale as Sauterne, and much of the Persian oil is devoid of colour, and fit to be burnt crude. That of Rangoon, on the contrary, is dense and dark as pitch, and that produced in Africa is equally heavy. In odour, too, it is not less distinctively varied, Canadian oil being remarkable for a peculiarly offensive smell, like that of garlic.

Petroleum is not, as commonly supposed, explosive, and as long as it remains in the liquid form will, even when ignited, burn gradually and steadily. It is the inflammable vapour evolved from it, which forms a fulminating compound in combination with oxygen or atmospheric air, and even this mixture requires contact with actual flame to kindle it, the passage of a spark or of incandescent metal not being sufficient. The fitness of oil for domestic use is determined by the temperature at which it gives off inflammable gas, technically known as its "flashingpoint," and various methods have been devised to apply this criterion. The earliest used was the "open test," so called because the oil, with a thermometer immersed, is heated in an open vessel, above the surface of which a flame is passed. As soon as the volatile vapour is given off in sufficient quantity, a pale-blue flash or flicker follows, proving the oil dangerous at that temperature. The Petroleum Act of 1868 prescribed a flashing-point of 100° Fahr. by this test, as the minimum for safety in general use. The "close test," invented by Professor Abel in 1876, consists of a covered vessel, an orifice in which is disclosed at intervals by a slide, at the same moment that a lamp swings across it. The vapour thus confined breaks into flame much sooner than when in free contact with the air, and a flashing-point of 73° Fahr. in the Abel apparatus, corresponds to 100° Fahr. in the open test.

It is a curious fact that petroleum has an affinity for lightning, which frequently explodes the surface gas and kindles the oil. Ordinary conducting-rods are found useless as a protection, and from April to August 1876, 242,412 barrels were thus destroyed in the United States, the tanks struck being invariably those with wooden covers.

Though deposits of mineral oil and bitumen are widely distributed over the globe, the great petroleum zone, where it is found in large quantities, lies mainly between the 35th and 45th parallels of north latitude. Within these comparatively narrow limits, it can be traced at intervals round the entire circuit of the earth, with a focal point, or centre of greatest production, in each hemisphere. The line of the prodigious deposits of the VOL. XVI.—NO. 1. [Third Series.]

D