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(\£J 



FOR GENERAL READERS. 



Vol. II. 



DECEMBER 14, if 



No. 24. 





PAGE 



Scientific Table Talk 



W 



Astronomy in China. (Illits.) 



S94 



Examinationism 



Soo 



The Utility of Bees 



,596 



Some Recently - Discovered Marine 





Crustacea. (Ilhis.) 



W 



Animal Geography 



598 



General Notes ... 



S99 



Simple Experiments in Physics. (/lias. ) 



601 



Antipyrine in Sea Sickness 



602 



Natural History — 





Fish out of Water. (Tlliis.) 



603 



CONTENTS. 



Herons and Heronries ... 



Colias Edusa at Woodford ... 



Miscellaneous Notes 



Teeth of Whales— Part II. ... 

 Reviews — 



Theoretical Mechanics 



Colour 



Macaws, Cockatoos, Parakeets, and 



, Parrots 



Abstracts of Papers, Lectures, etc- 



Geological Society 



Institution of Civil Engineers 



PAGE 





PAGE 



604 

 604 



Society of Engineers... 

 Belfast Natural History 



... 609 



and Philoso- 



604 

 605 



phical Society ... ... ... 6 10 



Royal Academy of Sciences, Amster- 

 dam ... ... ... ... 611 



606 



Miscellaneous Societies 



611 



607 



Flints 



612 



607 



Recent Inventions 



615 



Sales and Exchanges . . , 



616 



608 



Diary for Next Week ... 



616 



609 



Meteorological Returns 



616 



SCIENTIFIC TABLE TALK. 



By W. Mattieu Williams, F.R.A.S., F.C.S. 



A great deal of ingenuity has been expended on theories 

 that have struggled with the question of the origin of 

 petroleum. To those who, like myself, have been 

 engaged in the manufacture of petroleum, have produced 

 it in tons and hundreds of tons, all this learned discussion 

 appears very crooked and far-fetched. We know that if 

 certain kinds of coal are enclosed in any kind of sur- 

 rounding, such as an iron, or clay, or brick retort, and if 

 this is heated moderately and slowly, the slower and 

 more moderately the better, we obtain liquid hydro- 

 carbons not merely similar to the petroleum of the 

 natural springs, but actually the same ; that we obtain 

 gases and vapours identical with those that escape from 

 such springs, and we find left behind in our retorts a 

 material identical in chemical composition with anthracite. 

 Its mechanical structure is not quite the same ; it is more 

 porous ; but if this porous coke be subjected to such 

 pressure as that to which anthracite certainly has been 

 subjected it becomes anthracite. 



The simple inference, therefore, is that certain beds 

 of bituminous coal have been heated moderately and 

 slowly, and thus their volatile constituents have been driven 

 from them, as from that in our retorts, and that the 

 non-volatile coke has been left behind, as in our retorts, 

 and this having been subjected to the pressure of the 

 superincumbent strata, has acquired the form of com- 

 pressed coke, or anthracite. 



In controversion of this very simple view, we are told 

 that petroleum is not found associated with coal, but 

 that the springs occur in Silurian, Devonian, Cretaceous, 

 and other non-coal-bearing regions. This presents no 

 difficulty to the oil-maker, who is accustomed to attach 

 pipes to his retorts, and carry the oil vapour to con- 

 densers, and the liquid oil from them to considerable 

 distances from his coke. He knows that if his retorts 

 were porous and imbedded in other porous material the 

 vapours would penetrate that material, and there become 

 condensed when it reached a cooler stratum, and that 

 after condensation the liquid would flow downwards, 

 until it reached the limits of the porous material, and 

 that it would there accumulate. 



These are exactly the conditions under which many 

 coal-seams have been converted into anthracite. That 

 such conversion has taken place is proved by the fact 

 that there are seams from which the hydro-carbons have 

 been distilled at one end, that end being converted into 

 complete anthracite, the other end of the same unbroken 

 coal remaining highly bituminous, and the intermediate 

 portions forming a gradation due to varying degrees of 

 coking. Mr. Hull (describing the Russian coal-fields) 

 says, "It is a most remarkable circumstance, in connection 

 with the Donetz formation, that the same beds of coal, 

 from being highly bituminous in the western parts of 

 this coal-field, pass by imperceptible gradations into 

 anthracite in the eastern parts, in a manner analogous 

 to that of the South Wales coal-field in our own 

 country." 



We know how water-springs are formed, and we are 

 justified in supposing that petroleum springs are simi- 

 larly formed. As a striking and typical example of a 

 water-spring, I will take that of the celebrated St. Wini- 

 fred's Well, which has given its name to Holywell, in 

 Flintshire. Here, at a place that is otherwise not more 

 watery than the country generally, a stream of water 

 flows upwards from the ground, pouring forth the 

 enormous quantity of 21 tons, or 4,700 gallons, per 

 minute, equal to a daily supply of 6,768,000 gallons. 

 This forms a small river that runs down to the estuary of 

 the Dee. Why does the water issue there ? The answer 

 is very simple. The porous carboniferous strata and the 

 millstone grit of the neighbourhood both slope down- 

 wards towards Holywell; there they terminate in a 

 fault which presents to them a wall of compact lime- 

 stone, and thus the underground flow is suddenly 

 arrested ; but its sources being much higher than the 

 place of sudden arrest it, rises to the surface there, and 

 then overflows. Before doing this some of the water 

 has travelled many miles underground. 



If water can thus flow through the coal-measure 

 rocks and the millstone grit below them in Flintshire, 

 why should not the liquid, distillate from heated coal do 

 the same in these identical rocks at other places ? and 

 why should it not accumulate when it meets a barrier of 

 impervious limestone ? As a matter of fact, the richest 

 oil-wells like the richest water-springs, do actually occur 



