314 



SCIENTIFIC NEWS. 



[April 6, 1 888. 



elements is somewhat irregular, and we are all greatly 

 indebted to such investigators as Mr. Crookes for en- 

 deavouring to discover a cause for this irregularity, but 

 we cannot think that his present speculation is likely to 

 advance the subject very much. Moreover, it appears to 

 us that he rather begs the question by asking us to 

 suppose that the atoms of elements are not identical and 

 homogeneous. We have always understood that the 

 word element means a substance composed of an aggre- 

 gation of molecules, or atoms identical and homogeneous. 

 If therefore, this definition of the word element is to 

 hold good, it seems a contradiction in terms to talk of an 

 element not being composed of molecules or atoms which 

 do not fulfil these conditions. The question concerns not 

 only the fundamental principles of chemistry, but it has 

 a most important bearing on other branches of science ; 

 we shall therefore wait with interest its further dis- 

 cussion and development. No one can suppose that 

 what Mr. Crookes has now put forward is to be accepted 

 as final. 



SCIENTIFIC TABLE TALK, 



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



Medical science has made many " new departures " 

 during the century, one of the most remarkable of these 

 being the sending of tottering, emaciated patients suffer- 

 ing from deadly lung-disease to spend a winter amid the 

 snows of the Upper Engadine, a region described in 

 Murray's handbook as follows : " Owing to its high ele- 

 vation, and the icy barrier of enormous glaciers which 

 separates it from Italy on the south, it possesses a most 

 ungenial,nay, severe chmate. In the language of its inhabi- 

 tants it has nine months of winter, and three of cold 

 weather." In spite of this, consumptive patients go there, 

 remain for the winter, and many come back alive. The 

 mechanical purity of the atmosphere at such an elevation 

 is one of the factors to which its curative action has 

 been ascribed ; those invisible nuclei which Aitken has 

 shown to be necessary for the production of mists and 

 fogs are exceptionally few, if not absolutely absent up 

 there. 



But Aitken showed that burning or subliming sulphur 

 is the most potent of all known sources of fog-producing 

 nuclei, and now, according to the British Medical Gasctte, 

 a series of observations have been recently made which 

 prove that the inhalation of an atmosphere impregnated 

 with the fumes of burning sulphur, i.e., sulphurous acid, 

 operates most beneficially in arresting the progress of 

 pulmonary tuberculosis. Means of effecting such impreg- 

 nation, such as a lamp burning carbon disulphide, etc., 

 are described, but all these are objectionable in a well- 

 appointed house on account of the bleaching of upholstery 

 and corrosion of metal work which sulphurous acid effects. 

 If, however, no other means are available, these orna- 

 ments must be sacrificed rather than the lungs of their pro- 

 prietor. 



But there is a sanitorium within easy reach of 

 the London merchant who cannot leave his office to 

 winter in the Engadine or on the Riviera. There is the 

 underground railway. A season ticket between Moor- 

 gate Street and Edgware Road will provide him v;ith 

 luxurious cushions on which he can lounge at ease in the 

 intervals of business, read his daily paper and Scientific 

 News, while breathing an atmosphere constantly supplied 

 with the curative sulphurous acid. If this suggestion be 



successfully adopted, the enterprising chairman of the 

 company, Sir Edward Watkin, will be supplied with 

 another argument in favour of his Channel Tunnel pro- 

 ject. If the short tunnel of the Underground Railway, 

 with its numerous blow-holes, shafts, and station open- 

 ings into the upper air still retains so notable a supply 

 of sulphurous acid, how great will be its abundance in 

 a tunnel with a clear run of twenty miles under the sea, 

 where no such blow-holes, air-shafts, or station outlets 

 will exist. 



The origin of petroleum has suggested many theories, 

 the latest being that of Professor Medeleieff, who sup- 

 poses that water finds its way below the crust of the earth 

 until it meets with carbides of metals (particularly iron) 

 in a glowing state. The water is decomposed, its oxygen 

 uniting with the metal, while its hydrogen takes up the 

 carbon and ascends to a higher region, where part of it is 

 condensed into mineral oil and part remains as natural 

 gas, to find an outlet or remain compressed until a bore- 

 hole liberates it. We are told that he has made an 

 artificial hydrocarbon corresponding to the natural pro- 

 duct by imitating the theoretical conditions. 



My own theory, founded on practical experience in the 

 distillation of cannel coal and bituminous shales in Flint- 

 shire, is that what we did in our oil retorts, and what is 

 still being done in Scotland, in order to obtain British 

 paraffin oil, has been done more effectively and on a 

 grand scale by the internal heat of the earth acting upon 

 coal seams and bituminous shales. Such heat, combined 

 with pressure, would separate the volatile hydrocarbons 

 from coal and leave behind a compressed coke, or 

 anthracite, such as exists so abundantly in America. The 

 liquid and gaseous hydrocarbons would permeate the 

 porous rocks of the coal measures as water does, and 

 travel as water does until it finds an impermeable rock. 

 If such impermeable rock should contain cavities the 

 petroleum would settle there and remain in storage 

 until liberated by man or by natural disruption of the 

 rock. 



Petroleum is found in limestone rocks, and as every- 

 body knows limestone rocks are especially addicted to 

 caverns, mainly because percolating water dissolves them 

 gradually. Such limestone rocks underlie the carboni- 

 ferous rocks, very conveniently for such storage. When 

 an oil well is first struck it usually spouts — that is, throws 

 up a column of oil into the air. This gradually subsides, 

 and is followed by a rush of gas. Afterthis no more oil rises 

 spontaneously ; the spouting well becomes a pumping 

 well — one from which a certain quantity can be obtained 

 by pumping. In some cases the gas comes first. 



This is easily explained. If the borehole proceeds 

 directly to the highest part of the irregular roof of the 

 oil-filled cavern, the compressed gas at once escapes. If, 

 however, it strikes into a lower part of the roof below 

 the level of the oil surface, the elasticity of the compressed 

 gas above projects the liquid oil until its expansive 

 energy is exhausted, or the level of the oil reaches the 

 borehole. Then no more oil rises without pumping. 



In spite of proprietorship I hope that MedeleiefiTs 

 theory is correct rather than mine, for if it is, the supplies 

 of mineral oil and natural gas will be practically 

 unlimited as lower and lower depths of the earth's 

 interior maybe tapped for further production. If I am right, 

 there must be a definite limit to the supply, as there is to 

 the coal supply of any particular district, and as we are 

 rapidly proceeding towards theexhaustionofthecoalin our 



