532 



NATURE 



[July 24, rgi; 



devoted principally to theories on the formation 

 of petroleum, and to the composition of natural 

 crude oils. In the second lecture methods of com- 

 bustion for steam raising, and, briefly, its use 

 in internal combustion engines, were con- 

 sidered. Particular interest attaches to the 

 possible high efficiency attainable when utilised 

 for steam raising by Prof. Bone's surface com- 

 bustion system. It is, however, in the third 

 lecture that we find the all-important questions 

 of supply discussed. Euthusiastic advocates of 

 the advantages of oil fuel — advantages which are 

 admitted — often forget that, with small exception, 

 liquid fuel must always be an imported fuel in this 

 country, and that the questions of supply and price 

 must depend on a variety of factors, not the least 

 important being that of transport. Prof. Lewes 

 rightly emphasises the fact that trusts and rings 

 are by no means wholly responsible for the recent 

 high price of petrol ; there is the big question 

 of enormous increase in consumption with nothing 

 like a corresponding increase in production 

 Referring to this high price, Prof. Lewes says : — 



The way to keep the price of petrol within reason- 

 able bounds is not by letting the imagination run 

 riot on the subject of trusts and rings, but to develop 

 steadily all processes that will increase the supply, not 

 only of petrol, but petrol substitutes, always bearing 

 in mind that with the present consumption ever 

 increasing, petrol itself cannot supply the market for 

 even another ten years, and will probably be a raritv 

 as a motor fuel before the end of the centurv. 



This naturally leads to a reference to processes 

 for "cracking" heavier oils to produce lighter 

 fractions by the breaking down of the heavier 

 hydrocarbons, and a description is given of one of 

 these processes in which oil mixed with water is 

 sprayed through heated iron retorts filled with iron 

 turnings. 



Referring to sources of supply other than petrol- 

 eum oils, it is shown that shale distillation in this 

 country can yield only an infinitesimal fraction 

 of the petrol consumed. Benzene (benzol), ob- 

 tained from coal-gas and coke-oven tars, being 

 a native product of proved value as a motor fuel, 

 is discussed. Prof. Lewes says that if the whole 

 of the benzol from the 32 million tons of coal 

 annually coked in coal-gas and coke-oven practice 

 were recovered, a very considerable supply would 

 be assured, but under existing conditions less than 

 half the coke is obtained in recovery plant (it may 

 be noted that the use of recovery ovens is ex- 

 tending rapidly), and most of the benzol goes 

 abroad. Prof. Lewes appears to advocate re- 

 moving the tax on petrol and the imposition of a 

 tax on export benzol as a means of obtaining an 

 important addition to our supplies of motor fuel. 



Heavy fuel oils, suitable for steam raising and 

 for internal combustion engines, constitute 50 per 

 cent., or even more, of the crude oil. Prof. 

 Lewes anticipates no such shortage in supplies of 

 these oils in the future as has existed for some 

 time past, for " the distillation of every available 

 supply to yield petrol must result in enormous 

 volumes being thrown on the market." The 

 NO. 2282, VOL. 91] 



present shortage is ascribed to the better price of 

 petrol giving it preference for shipment during a 

 period when there is great lack of transport 

 facilities. With the increase in the number of 

 tank steamers (many yards are busy with such 

 vessels) he anticipates that the enormous stocks 

 held in many fields will become available. 



IS CANCER INFECTIVE? 

 l\TOT\\TTHSTANDING that no analogy has 

 -L ^ been shown to exist between cancer and 

 any known form of infective disease, the contrarv 

 is often asserted without proof, as a kind of creed, 

 by well-meaning and enthusiastic students of the 

 disease. A recent lecture illustrates the import- 

 ance of the influence the latter view may come 

 to have upon the public in general. Whether it 

 is wise to put forward such views before a non- 

 critical lay audience is open to doubt, even if the)' 

 are told "there is no risk of direct infection, 

 although it is better to avoid direct contact by kiss- 

 ing, by using in common table porcelain, clothing', 

 or beds." 



In a popular lecture 1 delivered at the Urania, 

 in Berlin, Dr. V. Czerny, the famous surgeon, 

 gives a clear account of the reasons why, after 

 forty years' experience in surgical practice, he still 

 holds that cancer is an infective disease. Ac- 

 cording to him it is communicable, not directly, 

 but through an intermediate host. Once the in- 

 fection is conveyed, the normal cells become 

 changed, they destroy the organism not only by 

 disturbing functions vital to life, but also because, 

 like real parasites, the cancer-cells withdraw neces- 

 sary foodstuffs, as well as secrete abnormal pro- 

 ducts of metabolism, viz. toxins which poison the 

 organism. Czerny supports his view by argu- 

 ments as to the varying frequency of the disease 

 in different countries and in different districts of 

 the same country, the alleged occurrence of epi- 

 demics of cancer, of the eyelid in cattle, of the 

 thyroid in trout, and of cage epidemics in mice ; 

 but he neither points out the statistical and 

 pathological fallacies that underlie the assertions 

 of the authors whom he quotes, nor takes cogni- 

 sance of the explanations more cautious authors 

 have given of the apparent differences and "epi- 

 demics " upon which he depends. Every pre- 

 caution necessary for the statistical study of cancer 

 in man applies with even greater necessity to 

 animals, since the data obtainable from an animal 

 population can be controlled at will by the in- 

 vestigator. Unless these precautions are taken, 

 weight may not be attached to reasoning from 

 such imperfect data without important reserva- 

 tions. 



Bugs, mucors, mites, worms, cockroaches, 

 bilharzia, filaria, acid-fast bacilli, &c, are alleged 

 as possible intermediate hosts of "the ubiquitous 

 cancer parasite," which may be a protist, but more 

 likely is an ultramicroscopic organism "which 

 constantly secretes a chemical irritant. If one 



1 "Ueber die neuen Bctrebuneen, das Los der Krebskranken zu verbes- 

 sern." Ey Dr. Czerny. Himmel und Era',-, Heft 7 , April, 1913. Also 

 published separately by B. G. Teubner, Leipzig and Berlin 



