1016

solid fuel burnt in an efficient appliance. It is easyto sympathise with his feelings, especially as mostpeople find a coal fire companionable, and somehave beautiful ancient grates which they wish to keep.Actually, much of the fuel saving of recent years

has been achieved in industry ; for there is some

legal restriction over all forms of smoke except thatfrom domestic chimneys. Much of this consists in

inflicting fines after the nuisance has been caused, butsome local Acts-such as the City of London (VariousPowers) Act, and the Manchester Act, both passed in1946, and a spate of others passed subsequently-aim at prevention. Thus the City of London Act

gives the common council power to make by-lawsrequiring that in new buildings, and in buildingswhere the heating arrangements are being sub-

stantially altered, the new equipment should bechosen " to prevent or reduce to a minimum theemission of visible smoke." Presumably this refersIto business houses rather than factories where furnacesare used ; nevertheless the abatement of smoke bysuch reguiations should be considerable. In manyindustries, Mr. MARSH notes, coal-fired kilns are beingreplaced by kilns using producer-gas, town gas, andelectricity ; and in many others better instrumentsfor measuring fuel consumption, more efficient controlof draught, and better stoking have made fuel wasteand smoke production negligible. The National’Smoke Abatement Society recommend niodernisation’of coal-burning’ plant, approval of new plant by acompetent authority, better training for stokers, moreresearch on pollution, and of course a greater use ofsmokeless fuel as this becomes available. Another

policy they favour is the setting-up of smokeless zones,such as the one planned for Manchester, where the1946 Act requires that " no smoke shall be emittedfrom any premises in the central area," and where thecorporation may, if it thinks fit, " contribute thewhole or part of the expense necessarily incurred byany person in making premises smokeless." (Unfor-tunately little active progress seems to have been

made yet, except in Salford, which is taking the lead.)Clearly such smokeless zones could begin as scatteredcentres, and be extended until whole cities were

included ; and the plan is flexible, and allows forminor infringements such as the production of smokewhen a cold boiler is being lighted up.Most of the Simon report’s thirty-five practical

recommendations still need trying. Meanwhile welive under a cloud. One of the weaknesses of our

position is that we can do little as individuals ; butthis situation was paralleled in the 19th century whenthe pioneers of public health were fighting our battlesfor clean water. The National Smoke Abatement

Society are doing much to create an informed publicopinion. Already before the war they were printingpamphlets to guide householders who wished to installbetter appliances, and they will always give advice tothose who ask it. Also the Solid Smokeless FuelsFederation 5 publish a brochure showing types of grateand recommending appropriate smokeless fuels. Thetrouble is that most of us have underdevelopedconsciences about smoke. But the periods of fog wehave already experienced this winter may para-doxically have lightened our darkness.

5. 1, Grosvenor Place, London, S.W.1.

The Cause of DiabetesTHOUGH nearly thirty years have passed since

insulin was discovered by BANTING and BEST, thecause of diabetes mellitus remains unknown. Butinterest is very far from flagging, as is shown by theBanting memorial lecture by Prof. F. G. YOUNGwhich we published last week and by the discussionhe opened at the Royal Society of Medicine on Dec. 14.In this discussion he pointed out that as " diabetesmellitus " may comprise more than one condition,and as there are several ways of inducing it experi-mentally, there are possibly many related problemsto be solved rather than a single one. The idea thatit exists in more than one form was also brought outby Dr. H. HARRIS in speaking on the genetic aspect.A series of 1241 diabetics, he said, was divided intotwo groups, according to whether they developed thedisease before or after thirty years of age, and it wasfound that the former, but not the latter, had asignificantly higher rate of cousin marriages in theparents; which suggests hereditary differences betweencases of late and early onset. _

Experimentally there are five main methods of

producing diabetes, at least four of which involvedirect or indirect interference with the pancreas.These five methods are : (1) pancreatectomy, com-plete or partial ; (2) the administration of alloxan,which brings about rapid necrosis in the p cells ofthe pancreatic islets ;, (3) the administration of

anterior-pituitary extracts, which may lead to a

persisting diabetes associated with lesions in, theislets ; (4) the administration of excessive doses of

glucose, which in a partially depancreatised cat (oreven in a normal one) may produce persisting diabetes,again also associated with’ lesions in the islets 1; and(5) the administration of certain adrenal corticalsteroids, which can cause glycosuria in animals. Wemust also mention the glycosuria that may follow theadministration of large doses of adrenocorticotropinto the rat 2 or to’man,3 which is presumably mediatedby the bypersecretion of adrenal cortical steroids.Professor YOUNG distinguishes between " idiohypo-pbyseal " diabetes, which exists during a period ofdaily injections of diabetogenic anterior-pituitaryextract, and " metahypophyseal " diabetes, which

persists after such treatment has ceased. The latteris associated with structural changes in the islets ofLangerhans, which have been clearly elucidated byMr. K. C. RICHARDSON, and perhaps it can exist clinicallyin the absence of any sign of pituitary hyperfunction.

Professor YOUNG has found that after takinga high-carbohydrate diet dogs are less sensi-tive to the diabetogenic action of anterior-pituitaryextract than they are after taking a diet containinga high proportion of meat protein. He has alsoshown that in the dog with metahypophyseal diabetesketonuria is much greater when the diet consistslargely of lean meat than when it contains a highproportion of fat. Relevant to these observations arethose of TEJNING,4 who estimated the volume of theislets of Langerhans in the pancreases of rats given1. Dohan, F. C., Lukens, F. D. W. Endocrinology, 1948, 42, 244.2. Ingle, D. J., Li, C. H., Evans, H. M. Ibid, 1946, 39, 32.3. McAlphine, H. T., Venning, E. H., Johnson, L., Schenker, V.,

Hoffman, M. M., Browne, J. S. L. Proc. Ass. Study int.Secretions (U.S.A.), 1948.

4. Tejning, S. Acta med. scand. 1947, 128, suppl. 198.

1017

different diets for about nine months, and found thata diet rich in protein, and also one with a high propor-tion of fat, caused diminution in islet volume, whichwas slightly raised, on the other hand, in the animalsreceiving a high-carbohydrate diet. In such experi-ments the comparative calorie intakes of the animalson the different diets may be of commanding import-ance ; and Prof. H. P. HIMSWORTH in the R.S.M.discussion did well to recall the dramatic fall indiabetic mortality in this country which followed theimposition of food-rationing during the 1914-18 war,and again during the late war. Mortality rose againafter the first world war but not after the second,when rationing was (as we are all well aware) éon-

tinued ; and there is a strong probability that thefalls in mortality had something to do with the restric-tion in people’s choice of food. Professor HIMSWORTH

pointed out that the curve showing reduction indiabetic mortality and the curve showing reduction inthe total fat content of the diet are remarkablyparallel. (Surprisingly enough, the protein contentof the diet of the nation as a whole has tended to riseduring the past few years, though it may well be thatthe meat protein component has fallen.) He wascautious in his conclusions, but his data supported theview that rationing has reduced the incidence, as wellas the mortality, of diabetes.

Dr. R. D. LAWRENCE reviewed the work done sincethe dramatic report in 1943, by SHAW DUNN and hiscolleagues,5 that alloxan causes necrosis of the &bgr; cellsof the pancreatic islets and consequent diabetes. As

yet, he said, there is no substantial evidence that

diabetogenic doses of alloxan are ever produced meta-bolically in the animal body ; indeed it is unlikelythat alloxan diabetes occurs naturally. But the valueof so simple a tool for the experimental induction ofdiabetes has been immense, and it is greatly to beregretted that Professor SHAW DUNN lived so short atime after his important discovery. So far alloxanhas unfortunately proved of little value in thetreatment of hyperinsulinism in human beings,though investigations continue.

Developing his suggestion that there are hereditarydifferences between diabetes appearing early andlate in life, Dr. HARRIS discussed observations thatfit the assumption that the milder cases of late onsetare heterozygotes for the abnormal gene, while thesevere cases of early onset are homozygotes. This

assumption would account for many of the factsalready known about familial distribution and popula-tion frequencies ; but, as Dr. HARRIS said, muchmore work is needed to test it. He has found thatin some families (mostly those with the disease inmilder form) diabetes picks out mainly the femalesand in other families mainly the males, and this

happens more often than it would if it were simplya random process. He also raised the question ofhow diabetes is maintained in the general populationdespite the fact that juvenile diabetics are liable todie before they have completed the reproductivephase of their life. One would expect that in eachsucceeding generation the genes determining thejuvenile type of disease would be less and less repre-sented. But the later the disease develops, the lesslikely is it to diminish effective fertility ; and Dr.

5. Dunn, J. S., Sheehan, H. L., McLetchie, N. G. B. Lancet, 1943,i, 484. Dunn, J. S., McLetchie, N. G. B. Ibid, ii, 384.

HARRIS mentioned an interesting observation thatthe proportion of women who bear a child or childrenmay actually be higher among " elderly " diabeticsthan among non-diabetics of the same age-group.There is no unequivocal evidence for a greater fer-tility among diabetic or potentially diabetic women,as compared with non-diabetics, but the suggestiondeserves further study.No adequate and simple conclusion about the

cause of diabetes can be drawn from the mass ofdata that is still accumulating. But the picture as awhole is becoming less rather than more confused.Careful analysis of hereditary factors in humandiabetes has already produced some simplifying hypo-theses, while the fact that the pancreatic islets areaffected by so many, apparently different, methods ofinducing diabetes is in itself encouraging. Dr. andMrs. CoRi, whose share in the Nobel prize for medicinein 1947 was so well deserved, have initiated researchesconcerning the in-vitro influence of hormones on -

the enzyme hexokinase which are of fundamental

significance ; and it is perhaps not too much to hopethat such investigations will one day reveal that

diabetogenic agents interfere at relatively few pointswith the normal processes of carbohydrate metabolism.That genetic, hormonal, and dietetic factors mayall, directly or indirectly, affect carbohydrate meta-bolism by influencing a single enzyme system—or atleast only a few such systems-is an attractive

possibility revealed by the research of the last fewyears.

Osteopathy" ABOUT things on which the public thinks long,"

said SAMUEL JoHNSON, " it commonly attains tothink right." And we have to accept the fact thatpublic opinion has come to lean on osteopaths forseveral types of treatment ; that kings, nobles, andthe common people patronise them ; and that themedical profession is widely blamed for its grudgingreception of the new ideas. In 1934 a Bill was intro-duced into the House of Lords,

" to place the practiceof osteopathy, as a developing system of treatment ofdiseases by manipulative methods, under the controlof a statutory board." One of its sponsors, LordELIBANK, argued that the Medical Acts were neverintended to put obstacles in the path of new methodsin the treatment of disease ; osteopathy, he said,was a new line of thought, and an Act was requiredto protect the- public from the malpractice of persons"

unqualified" in osteopathy. Lord MOYNIHAN, onthe other hand, denounced osteopathy as a spuriousscience,

" the derision of all competent and experiencedminds," and feared that if it were encouraged other-cults would soon be clamouring at the gates of Parlia-ment. In this he was supported by Lord DAwsoONOF PENN, who felt that the honourable path for the-osteopath seeking recognition was the arduous one-to qualify first, in order to obtain the privileges of the-doctor, and then to turn to his particular love, as- thehomoeopath has done for generations past.The Bill, after its second reading, was referred to a

select committee, which subsequently advised that itbe rescinded. During its discussion the fact emergedthat in the United Kingdom at that time there wereonly about 170 men and women,

"

qualified " in

osteopathy, though some -- 2000-3000 were engaged.