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condition of their patients in May, 1933, was astriking testimony to the progress that has beenmade. To take the possible failures first, one

patient died after ten days from a cerebral abscess,but the post-mortem examination gave justifiablegrounds for assuming that this had started todevelop before the operation. A second diedthree months after the lobectomy from an

influenzal pneumonia. Of the remaining eight,.six were healed and free from symptoms, whilethe other two were back at work, though notentirely cured. The lobectomy in eight of theseten cases was done for bronchiectasis and in theremaining two for carcinoma. ROBERTS and

‘

NELSON are strong supporters of the one-stageoperation, in which the lobe is cut away and thestump is closed by sutures, as opposed to the two-.stage in which the lobe separates as a result ofstrangulation. One of the great difficulties in

lobectomy is the limitation of the infection, andthis is effected in the one-stage operation bycompletely closing the chest wall after the insertionof an air-tight drain into the base of the pleuralcavity. This drain is connected by a tube whichopens under water in a Woulfe’s bottle. The

negative pressure in the chest causes the remaininglobe, or lobes, to re-expand and gradually fill

up the whole pleural space. The one-stagelobectomy is, moreover, a more truly surgicaloperation than the two-stage, which necessitateswaiting for the lobe to separate by sloughing.An even more remarkable achievement is

reported by EvARTS GRAHAM and J. J. SINGER,2who have successfully removed an entire left lungtogether with several mediastinal tracheo-bronchialglands. In this case the patient had a squamouscarcinoma of the bronchus of the upper lobewhich projected slightly into the bronchus of thelower lobe. Not only were the whole lung and theglands removed at one stage, but in addition,seven ribs, from the third to the ninth inclusive,were resected from the transverse processes to theanterior axillary line. This was done in orderthat the soft tissues of the chest wall could collapseagainst the stump to obliterate, so far as possible,the pleural cavity. Although a small empyemadeveloped in the upper part of the cavity, thewounds were all healed in three weeks. Thelatest repoit, four and a half months after theoperation, was very satisfactory.

In considering the brilliance of these results--and they are very brilliant-one must be gratefulalso for the steady advance in methods of anws-thesia. This has done much to enlarge the sphereof surgery ; and it will do more.

VITAMINS IN MILK

THE general opinion that cow’s milk is, on thewhole, rather a poor source of vitamins is contestedby Prof. H. C. SHERMAN in a paper read at therecent annual meeting of the American PublicHealth Association at Indianapolis.3 3 Vitamin A,he points out, is excreted in the milk with remark-

2 Jour. Amer. Med. Assoc., Oct. 28th, 1933, p. 1371.3 Amer. Jour. Pub. Health, October, 1933, p. 1031.

able constancy. Provided that it has been pre-viously well fed, a cow may continue to supplyvitamin A in normal quantity to her milk from herbodily store even during many months of sub-sistence on a diet poor in this vitamin. The highsurvival value for the species of vitamin A supportsthe view that evolution has in some measure

stabilised the vitamin-A content of milk, and thatit has further provided for the maintenance ofrelative constancy in this respect by the develop-ment of the body’s capacity to store this vitaminin times of abundant intake and to furnish it to themilk from this store when the intake is low. Whilethe vitamin-A content of the milk may be raised bythe feeding of cod-liver oil, fresh pasture, or kale,the vitamin-B content is " under physiologicalcontrol," in the sense that it cannot readily beraised above a normal value by the feeding of morevitamin to the cow, and that when this factor inthe milk has been artificially lowered by the feedingof rations very poor in vitamin B, the normalvitamin-B value of the milk is quickly regained assoon as the cow is again placed on a satisfactorydiet. The same holds true of vitamin C. Thoughmilk is not an outstandingly rich source of eitherof these vitamins, it appears to be a more

constant and reliable source than has hithertobeen appreciated.The methods of testing milk for vitamin-D values

have hitherto involved the employment of experi-mental diets of such drastic rickets-producingcharacter that only fairly high antirachitic potencieshave been demonstrable. With the use of moredelicate methods it is now being found that severalfoods including milk are more important sources ofvitamin D than previous work has indicated. Itstill remains true, however, that in northernlatitudes and in cities where the antirachitic valueof sunlight is greatly diminished by smokiness ofthe atmosphere, it is to the advantage of the infant,and possibly of older persons as well, to receivemore vitamin D than cow’s milk as commonlyproduced can be depended upon to supply. Forthis reason a considerable amount of attention is

being directed to increasing the vitamin-D contentof milk. Three different methods of enrichment

may be employed : (1) a vitamin-D concentrate,such as cod-liver oil, may be added directly to themilk ; (2) the milk may be subjected to irradiationby carbon arc lights of suitable strength ; (3) irra-diated yeast or other suitable irradiated materialmay be added to the diet of the cow. A fourthmethod, that of irradiating the cow itself, is at

present under investigation. Vitamins E and Gare difficult to assess, but there is reason to believethat vitamin G, at any rate, is present abundantlyin milk at all seasons of the year. Though it isperhaps true that in the United States of Americasupplementing of the infant’s diet with vitamin Dis adequate to bring about normal development, itis doubtful whether in this country completereliance can be placed on milk for the supply of thevarious other vitamins required by the growingchild.

There is a considerable amount of evidence thatboth vitamins B and C are precariously near the

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borderline of sufficiency. It must further beremembered that probably the major proportion ofcow’s milk fed to infants has been previously treatedby heat, drying, or condensing, and that in theseprocesses the vitamin C certainly seems to suffer.How many other factors are requisite for optimumdevelopment is not known. The tendency is toanalyse nutritive values by animal experimentationin the laboratory, and to record the results in termsof an ever-increasing list of vitamins. No one candoubt the value of this method, and its successes inthe past amply justify its continuance in the future.It must, however, be remembered that what holdstrue for rats and guinea-pigs may not necessarilybe true for human infants, and that the clinician isnot absolved by the laboratory worker from makinghis own practical observations. It by no meansfollows that a more or less synthetic diet with thevarious vitamins added, in as chemically pure astate as possible, will give the same results as thatof fresh cow’s milk. No laboratory worker would beprepared to say this. It is for the clinician, guided

by the results on animals, to make experiments onthe feeding of infants under his care, ascertainingwith due precautions on a sufficiently large numberof subjects the diet that yields in practice the mostsatisfactory results.A very similar view is put forward in a recent

paper by Dr. CHALMEBS WATSON.4 4 Discussingthe comparative value of raw and pasteurisedmilk, he criticises the premature acceptance ofmuch of the present teaching on vitamins, pointingout that we have at the moment insufficient

grounds for concluding that the beneficial effectof raw milk on nutrition and growth can be

duplicated by the addition to an insufficientdietary of purified vitamin preparations. WhileDr. WATSON states the case against vitamins ratherstrongly and without much supporting evidence,few will be found to disagree with his main thesisthat our present knowledge of the nutritive factorsin cow’s milk is very inadequate.

4 Scot. Jour. Agric., October, 1933, p. 394.

ANNOTATIONS

THE DENTAL ENTRY

Sir Francis Acland put a rule-of-three sum to theDental Board on Nov. 15th-admitting he had doneit before. If before the war, he said, 250 newlicentiates a year were needed to maintain a DentistsRegister of rather over 5000, how many licentiates(which means a larger number of entrants) wouldbe required to maintain a Register of over 14,000 ? ‘1The answer is 700, and the numbers of actual entrantskept fairly steady in 1927, 1928, and 1929, averaging210 for those three years. They rose to 275 in 1930,and there was a sudden increase to 406 in 1931, whichdeclined to 360 in 1932, and remained at this figurefor 1933. The only possible conclusion from thesefigures is, he said, that the Dental Board shouldcontinue to try to increase the numbers by continuingits policy of awarding bursaries with only suchlimitation as the limitation of its means requires.The treasurers of the Board, who have the task ofselecting those who are to receive bursaries to assistthem through their dental training, are finding thedifficulty increasing owing to the growth in numbersof those who apply. Help has been refused to nearlyhalf the applicants who came before the Board lastSeptember. Of the 51 applications refused 17 wouldhave been considered had it not been for the excessivecost which would have fallen on the funds if helphad been given. The selection committee hasconsidered various ways of reducing the number ofapplicants, such as insisting on the passing of one ofthe qualifying preliminary examinations of a higherstandard ; or selecting either by a competitiveexamination or on the marks obtained in preliminaryexaminations ; or fixing a lower income limit abovewhich no help will be given. After careful considera-tion a change in practice is suggested. " I wouldlike the Board to consider," said Sir Francis, " whetherwe should not give notice now that in two years’time we shall probably not be able to make any higheraward than at the rate of E30 a year." Exceptionwould be made in the case of sons of dentists and alsoof mechanics who had undergone sufficient trainingin dental mechanics to justify the shortening of theircourses in dental schools.

AVERTIN NARCOSIS

AN enormous amount of labour which has hardlyyielded commensurate results has been expended byNils Gyllensvard in studying avertin narcosis. His

original aim was to find through animal experimentsthe possibilities of intravenous drop narcosis withavertin in human beings. The outcome is the definiteconclusion that the method cannot safely be appliedto clinical practice. In the course of his experiments,however, so many other unsolved problems confrontedhim that most of the book is taken up with an accountof these and his efforts to elucidate them. Each

chapter starts with an account of the work previouslydone in connexion with the subject with which it

deals, and then goes on to describe the author’srelevant experiments, animal and human. The out-come of the whole is not always clearly stated, andto extract it from the detail of experiments and thepages of tables will tax the patience of the reader. Itis worthy of note that when he traces the use ofavertin in the world at large the author makes nomention at all of this country, where clinical recordshave been made which are at least equal in value toany of the continental ones. Questions to which heseeks an answer are the amount of avertin in thebody at different depths of narcosis and its concentra-tion in the blood ; also the strength of solution whichgives the safest and most convenient narcosis. Tothe last question the answer seems to be, accordingto this work, 3 per cent., and that is the strengthwhich most workers in this country have, we believe,adopted, if they do not prefer 2i per cent. For

quantitative estimation of avertin in body fluids andorgans Gyllensvard employed a method of his ownfor which he claims accuracy, and he also devised hisown method of measuring the depth of narcosis. Hisdeterminations with regard to the amount andrapidity of absorption of avertin from the rectum

approximate closely to those generally accepted ascorrect. Children, he finds, do not absorb the drugso well as adults-he does not believe that fat personsneed be treated differently from others as regardsdosage unless the obesity is really pathological.

1 Acta Chirurg. Scandinav., 1933, vol. lxx., Supp. xxii.,