August 29, 19 18] 



NATURE 



tillation of the material yielding it, accompanied by & 

 transference of the product to strata lying above those 

 in which its formation originated. According to some, 

 this process occurred at a definite and distant time 

 in the past, long subsequent to the formation of the 

 petroliferous strata ; but in the opinion of others it 

 may be in progress at the present time. The question 

 is not one of academic interest only, for it obviously 

 .would be of vast importance if it' could be demon- 

 strated that our stores of petroleum, which are being 

 depleted with alarming rapidity, might be replenished. 

 I fear, however, that there is no ground for such an 

 encouraging anticipation. As Lesley, the- United 

 States geologist, remarked in 1886 : — '' I am no geo- 

 logist if it be true that the manufacture of oil in the 

 laboratory of Nature is still going on at the hundredth 

 or the thousandth part of the rate of its exhaustion. 

 And the science of geology may as well be abandoned 

 as a guide if events prove that such a production of 

 oil in western Pennsylvania as our statistics exhibit 

 can continue for successive generations. It cannot be. 

 There is a limited amount. Our children will merely, 

 and with difficulty, drain the dregs." 



Probablv each of the views expressed in relation to 

 the organic origin of petroleum has some elements of 

 I ruth in it, and it is reasonable to assume that a sub- 

 -ance so varied in chemical and physical characters 

 as not in all cases been created under precisely the 

 -ame conditions or from an exactly similar source. 

 On the whole, however, the balance of evidence 

 appears to point to the conclusion that the petroleum 

 which we now find in the Palaeozoic and Tertiarv' 

 rocks is of substantiallv the same geological age as 

 the rocks themselves. It is, I believe, uncertain 

 whether man existed on the earth before the close of 

 tlie Tertiary period, but there is abundant evidence of 

 the existence of the human race in the following 

 Ouaternary period. The advent of mati mav, there- 

 fore, have been coeval with the completion of the 

 I rroliferous formations. 

 \ot less important than the provision of adequate 

 pplies of organic matter to be transformed into 

 iroleum is that of a suitable rock-formation for its 

 ception and conservation. For the latter we need a 

 porous stratum, such as coarse-grained sandstone or 

 conglomerate or dolomitised limestone, with an im- 

 pervious cover, such as that provided bv fine-grained 

 shale. In addition, in order that the wells drilled 

 may furnish individually a large yield of oil, it is 

 essential that the petroliferous strata should have 

 been caused to assume an anticlinal structure. Under 

 these tectonic conditions any natural gas accompany- 

 ing the oil accumulates at the crest of the anticline, 

 whilst the oil occuoies the flanks, and water is found 

 in the synclines. The gas often occurs at a pressure 

 many hundred povmds on the square inch, and it 

 obvious that in these circumstances a well drilled 

 into the flank of the anticline may produce an oil 

 fountain. 



The geographical distribution of petroleum is no 

 less wide than the geological, but the deposits mainlv 

 occur along well-defined lines, often associated with 

 the mountain rant^es. This is chieflv due to the 

 formation, in the elevators* orocess, of minor folds, 

 which have arrested and collected the oil in richly 

 productive belts, between more or less barren areas, 

 in the manner alreadv referred to. 



There are, however, but few of the localities indi- 

 cated as petroliferous which contribute largely to the 

 world's output of petroleum, estimated for last year 

 ^ approximatelv 70,403,128 metric tons. 

 The predominant contributor is the United 

 ates, which furnished no less than 64-74 P^^ 

 Tt. of the estimated total for 1017, the others 



NO. 2548, VOL. lOl"] 



in order of importance being : — Russia, with 

 13-26 per cent.; Mexico, with 11-37 per cent.; the 

 Dutch East Indies, wilht274 per cent.; Rumania, 

 with 208 per cent. ; India (Burma and Assam), Aith 

 i-6i per cent. ; Persia, with 1-32 per cent. ; Galicia, 

 with 0-947 P^r cent.; Japan, with 0-615 per cent.; 

 Peru, with 0-51 1 per cent.; Trinidad, with 0-303 per 

 cent.; Germany, with 0-189 per cent.; the Argentine, 

 with 0-170 per cent.; Egypt, with 0094 per cent.; 

 Canada, with 0037 per cent. ; Italy, with o-0o2 per 

 cent. ; and other countries, with 0006 per cent. 



It is not surprising that the flood of oil which has 

 been poured out by the wells of the United States in 

 ever-increasing volume since 1859 should now be at- 

 tended by signs of the approaching exhaustion of the 

 petroliferous territory, and it has been estimated by 

 Dr. David T. Day that, at the present rate of increase 

 of the output of petroleum, the known oil-fields of that 

 country will, on the basis of the minimum quantity 

 of oil obtainaWe, be exhausted by the year 1935. 



The oil-producing countries of the British Empire 

 are India (Burma and Assam), the West Indies 

 (Trinidad), arid Canada, and these in the aggregate 

 furnish only 2 per cent, of the total given. 



Under these conditions the British Government is 

 to be congratulated on having secured the control of 

 the exceptionally prolific oil-fields of Persia. 



In the British Isles, as is well known, there is a 

 flourishing industry in the mining and distillation of 

 Scottish shales as a source of mineral oil and am- 

 monia. This industry ovves its existence to James 

 Young, of Kelly. In 1847 Young's attention was 

 directed bv Playfair to a stream of oil flowing from 

 the top of a coal-working at Alfreton, in Derbyshire. 

 From this oil he succeeded in extracting, on a com- 

 mercial scale, paraffin-wax, lubricating oil, and burn- 

 ing oil. The supply of the raw material being soon 

 exhausted. Young attempted to imitate the natural 

 processes by which he believed the oil to have been 

 produced, by the action of gentle heat on coal, and 

 in 1850 made his invention the subject of his cele- 

 brated patent for "obtaining paraffine oil, or an oil 

 containing paraffine, and paraffine from bituminous 

 coals by slow distillation." The process was exten- 

 sively carried out in the United States, under licence 

 froni Young, until crude petroleum was produced in 

 that countrv in such abundance, and at so low a cost, 

 that the distillation of bituminous minerals became 

 unprofitable. 



In this connection it is interesting to note that, in 

 consequence of the approaching exhaustion of the oil- 

 fields of the I'nited States, attention is now being 

 actively given to the utilisation as a source of oil of 

 the immense deposits of bituminpus shales known to 

 exist in that country. 



I have mentioned the work carried out by Young 

 on. the crude petroleum of Alfreton, and this leads me 

 to refer to the prospects of obtaining free oil in 

 quantity in this country. For manv vears there was 

 an actual output of petroleum recorded in the General 

 Report and Statistics relating to Mines and Quarries 

 in the United Kingdom, issued by the Home Ofiice. 

 The annual output reached its maximum in 189^, 

 when it amounted to 200 tons, valued at 4.S8?. It 

 had fallen to five tons, valued at 12?., in 1899, and 

 was returned as nil in the following year. There was 

 a recorded production of eight tons in 190 1, and 

 twenty-five tons in 1902, none in the two succeeding 

 years, forty-six tons in IQ051, and ten tons in 1906, 

 the principal localitv of production for the latter years 

 being Dumbartonshire. Since 1906 no output has 

 been recorded. 



-Apart from the production referred to, there have 

 been discoveries of oil in this countrv from time to 



