NA TURE 



627 



THURSDAY, OCTOBER 22, 1908. 



INDUSTRIAL HYGIENE. 



Diseases of Occupation : From the Legislative, 

 Social, and Medical Points of View. By Dr. Thomas 

 Oliver. Pp. xix + 427. (London : Methuen and 

 Co., n.d.) Price los. 6d. net. 



THE present work deals witli one of the most 

 attractive branches of preventive medicine. It 

 is the time of legislative interference between 

 employers and workmen, and at no time has the 

 health of the community been held in higher regard. 

 If the regulation of the health of workpeople is to be 

 effected in that practical manner which has always 

 distinguished the progress of sanitary science in this 

 country, it is urgently necessary that those in whose 

 hands such regulation lies should be more thor- 

 oughly conversant with the medical side of the 

 problem. 



In a comparatively small book Dr. Oliver has 

 succeeded in bringing together a vast amount of use- 

 ful information on all sorts of subjects, ranging from 

 mining to mountain sickness and from anthrax to 

 the alkali manufacture. The most important section, 

 occupying nearly one-fifth of the book, is that dealing 

 with lead poisoning, in the suppression of which in 

 this country Dr. Oliver has played so prominent a 

 part. Very full treatment is also given to the effects 

 of organic and inorganic dust, a matter which has 

 to be considered in reference to a great variety of 

 trades. Ankylostomiasis is dealt with in detail in 

 the light of the author's own researches, and there 

 is a long, though not altogether satisfactory, chapter 

 on mining. 



We do not find, however, any adequate discussion 

 of several problems which concern nearly all trades 

 alike — the question of the temperature of factories, 

 &c., for example — and it is certainly time that some- 

 one undertook seriously the discussion of the influence 

 of slightly vitiated atmospheres on the health of 

 workfolk. The subject is throughout treated almost 

 entirely from the point of view of the medical man 

 and the pathologist. It is to be regretted that the 

 actual manufacturing processes are not given more 

 fully. A proper understanding of these is necessary 

 both for the consideration of the scientific questions 

 involved and to enable the medical man to adjust in 

 some part his idealism to the needs of practical life. 

 The solution of the diflficulties presented by trade 

 diseases must at any rate begin by some sort of com- 

 promise between the manufacturer and the doctor. 



Such pleasant reading do Dr. Oliver's chapters 

 make that one may not realise at the moment that 

 the information one has absorbed is of a peculiarly 

 elusive kind. The facts with which he has dealt are 

 not drawn up in any very orderly array, and through- 

 out one finds a certain vagueness which may well 

 tend to make the reader feel that he is treading on 

 ground too uncertain to bear definite action. Our 

 knowledge of industrial hygiene is sadly defective, 

 but the general principles which must underlie pre- 

 ventive measures are in many cases already suffi- 

 NO. 2034, VOL. 78] 



ciently well assured to bear definite enunciation. We 

 do not suppose, for example, that Dr. Oliver really 

 believes that there is any multiplication of individuals 

 in Ankylostoma outside the human bod)- ; yet he 

 leaves this absolutely fundamental question vaguely 

 unsettled. To laymen who are not acquainted with 

 details, and therefore not in a position to form 

 their own conclusions, this must be very unsatis- 

 factory. 



In some places where definite directions are given 

 they are contradictory ; thus in the chapter on rescue 

 apparatus for use in mines we find (p. 406) : — " Any 

 person attempting to do rescue work should therefore 

 be provided with not less than i cubic foot of oxygen 

 per hour " — i.e. less than half a litre per minute, an 

 altogether inadequate amount — and later (p. 408) : — 

 " A man about to undertake rescue work should be 

 given a continuous supply of 2 litres of oxygen per 

 minute." Written by a scientific man in part at 

 least for the use of the " general reader," we should 

 expect to find evidence that the scientific data were 

 stated with particular care. Yet without looking 

 beyond the same section (p. 407) we find that " liquid 

 air contains 2 parts of oxygen to 1 part of nitrogen," 

 the proportions, of course, being subject to consider- 

 able variation, and " in respiration only 4 per cent, 

 of the oxygen inhaled is taken up by the blood," in- 

 stead of about 20 per cent. 



The chapter on compressed-air and caisson disease 

 is perhaps the least satisfactory. The author appears 

 to accept the "soda-water-bottle theory," but he 

 dallies so long with the notions that a small excess 

 of carbonic acid in the air, mechanical repletion of 

 the visceral veins, and frictional electricity are im- 

 portant factors that one is almost compelled to agree 

 that " there is still much to learn as regards the 

 causes of caisson disease." As a matter of fact, the 

 work of Paul Bert, Leonard Hill and others leaves 

 no reasonable room for doubt that the " soda-water- 

 bottle theory " is correct. To encourage any longer 

 the theory of Snell that carbonic acid has any 

 material influence in practice is to stimulate local 

 authorities to waste huge sums of money upon extra- 

 vagant ventilation of caissons. 



The recommendations for the prevention of caisson 

 disease are not only indefinite, but also very unsound. 

 Dr. Oliver considers 3 or 5 minutes per atmosphere 

 of pressure as a safe time to allow for decompression, 

 and quotes the experience at the Bakerloo tunnel that 

 the cases of illness were not diminished by extending 

 the time of decompression from i| to 6J minutes. 

 The truth is that all these times are so much too 

 short that one is not likely to be much better than 

 another ; some 30 to 60 minutes are required for real 

 safety. Dr. Oliver commends, but fortunately does 

 not detail, the Dutch regulations; these, in fact, pre- 

 scribe that the rate of decompression should become 

 quicker as the pressure falls, a procedure which, if 

 applied to decompression from high pressures, would 

 without doubt kill many people. In the pages devoted 

 to diving, he states that divers should descend slowly ; 

 he does not explain why, perhaps because there is 

 no reason except that a slow descent increases the 

 risk. 



C C 



