594 



SCIENTIFIC NEWS. 



[Dec. 14, if 



where porous strata encounter compact rocks, usually 

 limestone rocks. 



• §"A little reflection will show that the demand of those 

 who say that if petroleum was formed from coal it 

 should be found associated with it is one that asks for a 

 physical impossibility. All who have had to do with 

 coal-mining know, to theircost, that the rocks both above 

 and immediately below ordinary coal-seams are freely 

 permeable by liquids, as their pumping machinery and 

 pit-tubbing proves, and therefore any liquid hydro-carbon 

 that may have been formed in heated carboniferous 

 strata in times far distant must have percolated far away 

 from the seat of its origin, must have travelled as far as 

 the porous rocks extend, even though that be hundreds 

 or even thousands of miles distant. This would 

 especially occur where the coal-bearing strata were 

 covered with compact rocks of later formation, not per- 

 mitting surface water to reach them, and such has been 

 the case and is the case with those deeper coal-bearing 

 strata that by reason of their depth must be heated. 



Reflecting a little further on these facts, we may arrive 

 at a very consolatory economical conclusion. It is 

 well known that there is much coal far below human 

 reach, the chief impediment to working it being the 

 steadily increasing heat of the earth as we proceed down- 

 wards. If I am right in the above we may not lose all 

 that fuel ; the coke may remain hopelessly buried, but 

 the hydrocarbons distilled by the heat into vapours will 

 force their way, in gaseous condition, through the heated 

 rocks, very slowly, but not less surely, until they come 

 to cooler strata, then they will condense and accumulate 

 where their further progress is barred by compact rocks, 

 and thus their richest constituents, the hydrocarbons, 

 may be utilised by man as gas-wells and oil-wells, such 

 as abound in Pennsylvania, such as pour up from the 

 sea-bottom on the Californian coast, such as have been 

 running to waste for thousands of years into the Caspian, 

 and such as have formed the great paraffin-pitch deposits 

 of Trinidad. 



It should be noted that limestone rocks are specially 

 addicted to cavern formation, owing to their solubility in 

 water charged with carbonic acid, that in some places 

 these caverns extend for miles as tunnels, through 

 which subterranean rivers flow, and in which sub- 

 terranean reservoirs are standing. The phenomena dis- 

 played on boring into the American oil-wells indicate the 

 existence of similar reservoirs of oil in the limestone 

 rocks, oil that has probably found its way there through 

 fissures. 



In reference to the theory of animal origin of petroleum, 

 I cannot refrain from reminding its advocates that their 

 objection to the theory above advocated, based on the non- 

 existence of oil with coal, applies to their own theory, as 

 the quantity of animal matter demanded vastly exceeds 

 that of the few fossils found in the oil regions. 



Besides this, it should be understood that while petro- 

 leum has the same composition as the paraffin distillates 

 obtained by slowly heating certain kinds of coal, both 

 crude petroleum and the solid paraffin wax it contains in 

 solution are widely different, both in composition and 

 properties, from the adipocere which is supposed to be 

 the animal basis of petroleum. Adipocere is a complex 

 soap ; Chevreul found it to be composed of a large 

 quantity, of margaric acid and a small quantity of oleic 

 acid, combined with ammonia, potash, and lime. Fourcroy 

 describes it as an ammoniacal soap. Petroleum contains 

 neither of these substances, but a series of special hydro- 



carbons of the marsh-gas series, i.e., of the products of 

 vegetable composition. Adipocere is readily decomposed 

 by atmospheric and other chemical agencies. Paraffin 

 derives it name (parum affinis) from the stability due to 

 its chemical apathy. 



It is a mistake to state that no petroleum is found 

 associated with coal. I visited a coal-mine in Shropshire, 

 known as the " tarry pit," where it ran down the sides 

 of the shaft and filled the "sumph" below. A publican 

 in South Staffordshire found a gas-jet, like those of 

 Pennsylvania, in his cellar, lighted it, and sold much 

 beer in consequence to curious visitors. But for reasons 

 above stated the accumulation of large quantities is im- 

 possible in such places. 



■ — ■^•s^wf**?-* 



ASTRONOMY IN CHINA: THE PEKIN 

 OBSERVATORY. 



WICE-ADMIRAL MOUCHEZ has just received from 

 Pekin, for the Astronomical Museum which he 

 has founded in connection with the Observatory of Paris 

 a series of photographs representing the Pekin Observa- 

 tory and the instruments there erected. By the courtesy 

 of our contemporary La Nature we are enabled to place 

 these curious views before our readers, and thus give 

 them an exact idea of the present state of astronomy in 

 the nation which has cultivated it with the greatest zeal, 

 for the longest time, and among whom it has received 

 the most remarkable developments. 



Astronomical functions have not ceased to be held in 

 honour in China, and the Observatory of the Celestial 

 Empire is at present under the direction of an uncle of 

 the Emperor, who ranks as the fifth prince of the blood, 

 and bears the title of Chancellor. 



The number of persons attached to this establishment 

 is more considerable than that at Paris. It amounts, 

 including students, to 196. The chief functionaries after 

 the Chancellor are a Chinese director and a Tartar 

 director, having the right to wear a button of a precious 

 stone, and to bear on the chest the image of a sea-raven. 

 Then follow two sub-directors, one Chinese and one 

 Tartar, and two assistants entrusted with calculations. 

 These latter, prior to the expulsion of the Jesuits, were 

 always foreigners. Two other functionaries require to 

 be noted. The first is the keeper of the buildings, and 

 the second the custodian of the water-clocks, as chrono- 

 meters have not been as yet introduced into the observa- 

 tory, any more than have telescopes. 



The calculators of the Observatory possess tables con- 

 structed or rectified by the Jesuits in the seventeenth 

 century, which are used in their calculations, and which 

 they keep carefully hidden. Hence, contrary to the 

 general principles of the Chinese Government, the astro- 

 nomical functions have become hereditary. But on the 

 other hand, they are purely honorary. 



The strictly scientific functions are not very difficult to 

 execute, since in Pekin itself there are some private 

 observatories attached to the European embassies. 

 Besides, the missionaries have organised at Zi-ka-wei an 

 observatory of the first rank, where all the modern 

 methods are carried out with carefully selected instru- 

 ments. This establishment is situate at 800 kilometres 

 to the south-east of Pekin, in the neighbourhood of 

 Shanghai. The astronomers of the Chinese Government 

 can thus, with little trouble, carry on the conversion of 

 the calculations. 



