957THE GAZOTHERM.—STUDIES IN; VACCINIA.

severe local reactions, while intraperitoneally it is

fatal though the cause of death is not quite clear. Themost interesting observations, however, relate to theintravenous injection of the poison. In large doses itcauses death within a few minutes, due, apparently,to intravascular thrombosis. After sublethal doses thecoagulation time of the shed blood is much accelerated,though in vitro silica has no influence on the rate ofclotting. Daily injections of sublethal doses causesdeath of the animal in three or four days, withdegeneration of the liver and kidneys and of vascularendothelium. The second paper describes the effectsfollowing the administration over long periods ofsmall doses of silica varying from 1/20th to 1/3rd ofthe lethal dose. The injections were made intra-venously, and the smaller doses were given daily, thelarger once a week. Animals treated in this way forseveral weeks show, when killed, a considerable degreeof fibrosis of the liver and a slighter fibrosis of thekidney and spleen. It is not quite clear how theselesions are brought about. The admirable illustrationswhich accompany the paper rather indicate that theprocess consists in a primary proliferation of thesupporting connective tissue of the liver, though theauthors appear to regard it as a process of repairfollowing injury to the liver cells. Possibly furtherwork will clear this point up, and it is one of obviousimportance. The chronic fibroses which are so commonin human pathology are obscure and difficult toexplain. Since it is no longer possible to lay theblame for the hobnail liver on alcohol, we are hard putto it to account for this common lesion, and it is quitecertain that the last word has not yet been writtenon chronic interstitial nephritis. The chronicinsidious diseases are the really difficult ones tounderstand, and there can be no doubt that this workmarks an important step forward in our knowledge ofvisceral sclerosis. It is a promising field for researchwhich should yield valuable results.

THE GAZOTHERM.

A LUNCHEON was held at the H6tel Métropole onMay 3rd, the guests being invited to meet Dr. Guebel,of the Paris Dental School, who desired to demon-strate a new dental apparatus, the Gazotherm. This.apparatus was invented by Dr. Fabret, of Nice, whoclaims for it that by its use filling operations on the,teeth can be carried out painlessly. The essentialfeature of the device is that a stream of oxygen isdirected on to the tooth to be filled. The tempera- ’,ture of the oxygen is lowered by passing it through achamber connected with a cylinder of compressed Icarbon dioxide which is gradually turned on. Theintense cold produced freezes the pulp so that thetooth becomes insensitive. This stage is deter-mined by noting the appearance of a film of frost onthe enamel. The apparatus is complicated and incon-veniently large, though apparently easy to manage.We understand that the cost is about 100; so thatits use among dentists is likely to be limited, at anyrate, until its practical utility has been more con-clusively demonstrated. ,

,

Dr. Guebel stated that the process, was quite.harmless, and that death of the pulp never resulted ;indeed, he went further, and said that only the proto-plasmic and nervous filaments which extend from thepulp into the dentine were frozen, and that the pulpitself was unaffected. It would be interesting toknow the evidence for this, since it must be extremelydifficult to ascertain the exact limits of the freezingprocess. It was admitted that the stream of oxygenmust never be allowed to impinge on the soft tissues,for it is obvious that, if the gum were frozen, therisk of gangrene would be considerable. This wouldseem to limit the use of the method to the frontteeth. Even so, the current of gas being underpressure must send out a spray, and it seems to usthat it must be difficult, if not impossible, to preventthe gum margin from being affected in some cases.These precautionary, statements are necessary in:

dealing with a new method, even though it may presentpromising possibilities ; it is unlikely, however, thatit. could ever meet.the claims made for it in a brochurewhich the promoters of the demonstration providedfor their guests-most of whom, by the way, seemedto be laymen. It is only fair to Dr. Guebel to saythat his name did not appear as the author of thepamphlet in question. The scope and limitations ofthis invention have yet to be learned in this country,but we hope that dentists who have the opportunitywill investigate it carefully under scientific condi-tions and make known their results to their colleaguesin the proper way-namely, by communication to adental society, when instructed debate upon its meritscan appear in professional journals. A device whichcan only be used in a professional consulting room orclinic and by a professional dentist should be intro-duced professionally. Demonstrations have beenmade, we understand, by certain firms to particulardentists ; a commonplace of commercial procedure,but not providing the expert criticism that is required.

INSTITUTIONAL CATERING.

ANYONE who is evolving for himself a system ofinstitutional management will get great help from theStanding Orders of the R.A.M.C. (Harrisons, St.Martin’s-lane, London, W.C., 1s.) to which MissMuncaster referred in her address on InstitutionalFeeding, published in THE LANCET of April 22nd. Beinga collection of Government regulations, it is not exactlya training manual, but nevertheless, nearly everythingis provided for, the salient idea being that no mistakeshall occur, and no loss fall upon the taxpayerexcept through a neglect of some specific regulation,for which the offender can be definitely - charged,convicted, and punished. We all know a cook shouldsend dinners up hot, but here it is laid down as hisduty, and if he fails he has committed a servicecrime. Thus the quartermaster’s duties in regard toprovisions are stated at length. He demands themin accordance with scale and requisitions ; by hissteward he receives and inspects them, acknowledgingtheir receipt in correct quantity and quality, unless onthe receipt he states to the contrary ; he watches theamounts in store, sees he is ready for any probabledemands, but permits no undue accumulation, andissues first the articles longest in store. He is respon-sible that the weights and measures used are accurate.He keeps the ration account, the dripping book, andthe fuel and light account, and trains N.C.O.’s to keepthem too. The cook draws his stores from the steward,certifying they are fit for use. Having cooked thefood he is to send it up hot, and after dinner he hasthe kitchen cleaned, the tables- scrubbed daily, thefloor at least twice a week, the walls brushed down, andthe windows cleaned once a week. Metal cooking-pots are washed out with hot water and soda afteruse, are cleaned, emptied, and carefully dried everynight; no pans are to boil dry ; range flues are to becleaned daily, and ovens washed out occasionally.Everything is provided for, and any manager con-structing his own plan of institutional catering willfind the book a real help. ’

STUDIES IN VACCINIA.

THE paper published by Dr, Myer Coplans in theApril number of the Journal of Pathology and Bacterio-logy-being certain collected studies in connexionwith the Beit Fellowship on the subject of vaccinia-is of special interest in view of the risk of epidemicsmall-pox in Great Britain since the practice ofprotective vaccination has been allowed to fall intodesuetude. In a recent pamphlet issued by the ResearchDefence Society it was estimated that of the popula-tion of the United Kingdom over 15 millions requireto be vaccinated or revaccinated to meet this risk.It has been the policy of the Government to maintainat their Lymph Institute at Hendon a reserve supply

958 CONGENITAL STEATORRHCEA AND PORPHYRINURIA.

of 2 million doses of calf lymph in cold storage. Inaddition, it may be assumed that private lymphmanufacturers in Great Britain also hold reserve

stocks amounting in all, perhaps, to as much as

half a million doses. Thus the total availableemergency supply in the country amounts to 2 milliondoses.The question of the quality of the lymph is of

outstanding importance. Lymph, as prepared by theordinary process of emulsification with glycerine andwater, and necessarily stored for several months-so-called " mature " lymph-may at length berendered free from pathogenetic organisms ; it isnever entirely bacteria-free. In the event of suddenepidemic requirements, it may be taken as reasonablycertain that all available " matured " stocks willrapidly become exhausted, and, as has occurred onprevious occasions, immature stocks, rapidly prepared,containing pathogenetic organisms, will be placed uponthe market. Hitherto there has been no Governmentcontrol to prevent this. In time of panic the risk of con-tracting a septic complication in vaccination is alwaysconsidered preferable to an attack by small-pox. Inhis paper Dr. Coplans gives a simple method wherebybacteria-free calf lymph is prepared within 15 daysor even less. The essential special selective bactericidalsubstance added to the phenol-glycerine lymphemulsion is a triphenyl-carbinal dyestuff-e.g., mala-chite green or brilliant green-which, upon the termi-nation of its intense bactericidal activity, is convertedinto the comparatively innocuous leuco-compound byreduction, this process resulting in the immediaterestoration of the original colour of the lymph. Testscarried out showed that the longevity of the lymphprepared in this manner could be relied upon for18 months, storage in the meantime taking place at7° C., while the use of a refrigerator was avoided.The conversion of the dyestuff which is toxic, bacteri-cidal, and in high concentration, vaccinicidal, intoits comparatively innocuous form-viz., the leuco-compound, is an important development in laboratorytechnique as applied to biological problems. Itis an aphorism amongst lymph manufacturersthat the younger the lymph the more potent thevaccine. A by no means inconsiderable proportionof the epidemic reserve stocks are never used ;with the passing of time their potency diminishesand ultimately they become discarded. The cost ofstorage, supervision, and constant re-testing is alsohigh. All these items being properly taken intoaccount the cost of production of calf lymph has beennecessarily high, but by the method described, inaccordance with which Dr. Coplans has prepared over600,000 doses of the material, lymph of a much higherstandard of purity as regards bacterial content isprepared within a few days, as actuallv required, andthere is necessarily a great saving of cost, amountingin some cases to as much as 90 per cent. We thereforeconsider that this newer time-saving method ofpreparation must rapidly oust the costlier methodshitherto in vogue, and doubtless the Public HealthCommittee of the League of Nations, with its enor-mous task of small-pox control in Eastern Europe,will welcome any hope of lessening the nnancialburden in their present straitened circumstances.

It seems pertinent to recall, at this stage. that atthe present time any person may make or offer for salewithin the United Kingdom calf lymph vaccine,whatever its origin or quality, without qualification.let or hindrance. No statutory control is exercised,nor are the provisions of the Sale of Food and DrugsAct made to apply. Nowhere is it authoritativelylaid down as to what constitutes calf lymph either asregards purity or freedom from bacterial contamina-tion or as to potency. The Pharmacopoeial Com-mittee of the General Medical Council could randeiservice here by recognising calf lymph vaccine as

coming within the range of recognised materia medica.Further, the origin of the seed stock used for thepurpose of making calf lymph is important. Before1900 Parliament ordered the destruction of all seedstock of variolous origin at their Hendon establish.

ment, but left private manufacturers to their owndevices. Seeing that all laboratories, both English andcontinental, habitually interchange

" seed stocks "-all of them of variolous origin-it is difficult tounderstand how far Parliament was obeyed. Later itbecame the practice at Hendon to revive fast-fadingvaccine lymphs by interpolation of the rabbit, andrabbit-pox replaced the " vaccine seed of variolousorigin." Abroad, in place of the rabbit, the ass or themule is employed, and the resulting ass-pox, or mule-pox is used as the exalted seed stock for the vaccina-tion of calves. Such lymph is freely admitted to theUnited Kingdom for the purpose of sale, and nopractitioner knows whether the lymph he employs isderived from small-pox, rabbit-pox, ass-pox or mule-pox. We therefore consider that the time is ripe forthe Government to lay down some regulations uponthis matter for the protection of the public. Thepreparation of bacteria-free and fully potent vaccinelymph has enabled Dr. Coplans to carry out certainimmunising experiments upon the rabbit which, it isfound, can tolerate the repeated injection, given intra-peritoneally, of massive doses, each sufficient for thevaccination of 500 children, with the result that a highdegree of immunity is established. The writer laysdown a standard vaccine unit and doubtless will, ata later date, furnish details of the exact degree ofimmunisation produced. We shall look forward withinterest to his report on the fate of the leuco-compounds in the animal body.

CONGENITAL STEATORRHŒA AND

PORPHYRINURIA.

THERE are certain individuals who are abnormalfrom birth, in that they exhibit some deviations fromthe normal course of metabolism-functional analoguesof structural malformations. Such anomalies weredescribed by Sir Archibald Garrod in a lecture entitledMore Inborn Errors of Metabolism, delivered at theInstitute of Pathology and Research of St. Mary’sHospital on May 4th. He referred briefly to four suchanomalies, albinism, alcaptonuria, cystinuria, andpentosuria, which had been discussed in his Croonianlectures in 1908.1 These anomalies are all very rare,occur about twice as often in males as in females, andare apt to affect several collaterals in a family. Twoother errors may now be added to the list-viz.,congenital steatorrhoea and congenital porphyrinuria,which are no less rare, and equally curious. Congenitalsteatorrhoea is characterised by the passage, frombirth onwards, of stools in which liquid fat, whichsolidifies on cooling, is passed with the faeces ; a

phenomenon which has long been known as speciallyassociated with disease of the pancreas. Thelecturer referred to investigations carried out by Dr.W. H. Hurtley and himself 2 upon a boy aged 6 years,and those made upon a second case, in a boy aged 3years, by Drs. Reginald Miller and H. W. Perkins. 3Neither patient showed any signs of illness apart fromthe steatorrhoea, and tests of hepatic and pancreaticefficiency gave no indication of disease of the liver orpancreas. The proportion of fat in the dried faeceswas abnormally high in both cases, and in the first casethere was a pronounced excess of neutral fat, as com-pared to fatty acids and soaps, especially when a dietrich in fat was taken. In the second case the excesswas less pronounced. Utilisation estimations, bycomparison of the fat passed with the fat taken, showedthat in the first case the percentage of fat not utilisedremained constant when the fat in the diet wasdoubled, whereas in the second case the loss increasedthe more fat taken. This striking difference ofbehaviour can be matched among the pancreatic casesof steatorrhcea in which such estimations have beencarried out. The cause of steatorrhcea, as distinguished

1 Inborn Errors of Metabolism. London : Henry Frowde andHodder and Stoughton. 1909.

2 Quarterly Journal of Medicine, 1913, vi., 242.3 Ibid., 1920, xiv., 1.