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carried to excess. FRANCIS POLLER has not found shortand ultra-short wave therapy particularly valuable ;physicians from the United States quoted cases

which suggest that diathermy is just as efficacious.To sum up, although this Ninth Congress brought

no great new discovery it has cleared up many prob-lems of diagnosis and treatment and brought outnew principles and objectives. Apart from skindiseases caused by external infections, it seems thatthe time is not far distant when the use of ointmentsin dermatology will be almost extinct. What hasbecome chiefly important, for efficient diagnosisand for efficient treatment, is a knowledge not ofthe changes discovered but of their underlyingcauses.

LONDON WATER

SOME PRESENT-DAY PROBLEMS

Colonel Harold’s first report 1 as Director of WaterExamination to the Metropolitan Water Board isfull of interest, for, as he says, he came from thecomparative quiet of a peace-time army into the heartof the Board operations at a time of national

emergency arising from two years’ drought when itbecame necessary to consider ma,tters of high policy.London was, however, saved from anything more thananxiety and inconvenience owing to the huge storagesystems built up in accordance with the wise policyof his predecessor ; and the danger being ovar

Colonel Harold feels free to poke a little fun at theLondoner who talks about a condition of droughtwhen he has sufficient water for all purposes, includinga daily long bath. He compares it with the water

shortage of an Eastern war-time cantonment, wherethe daily issue resolved itself into a petrol drum ofwater, derived from brackish underground sources,receiving the unpurified road washings of an unpavedEastern town. But the shortage ot water in London,such as it was, led to the relaxation of a provisionin the Thames Conservancy Act of 1932 that everyday 170 million gallons of water must pass over

Teddington Weir. This eased the situation, butthe reduced flow of the river must have reacted onthe condition of the tJ’dal reaches if only to a smallextent. At Barking sewage carried upstream by thetide gave rise to many complaints from those usingpiers and boats. The total volume of water in theThames between Barking Creek and TeddingtonWeir amounts at low tide only to some 8000 milliongallons and the average content is 15,700 gallons,while the incoming water each tide is about doublethe low tide figure. The minimum statutory flowof fresh water over Teddington Weir of 170 milliongallons per day obviously bears to the average volumementioned the ratio of 170 to 15,700 or 1 to 93.A reduction of 30 million gallons per day in thestatutory flow would change this ratio of fresh totidal water to 1 to 113, a change which could havelittle adverse effect on the Pool of London. Alsoit should not be overlooked that some of the extrawater abstracted from the river must ultimately reachthe sewers and dilute the effluent which is passed into+1i< Tns

TASTE TROUBLES

Apart from this special source of complaint Londonconsumers found little. to grumble about last year.The complaints reaching the offices of the Board

1 Metropolitan Water Board. 29th Annual Report by Lt.-Col.C. H. H. Harold, O.B.E., M.D., D.P.H. London : P. S. King andSon. 10s. 6d.

numbered no more than one three-thousandth of aper cent. of population served. Only half of thesewere complaints about taste, and again only halfwere accepted as valid after investigation. Strictlyspeaking the responsibility at law of the Water Boardterminates at its mains-no small liability in itselffor there are 7760 miles of them. But in practiceall complaints are investigated on account of the

light which they may throw on adventitious pollution.During the year definite pollution was twice tracedto cross connexions of piping in important buildings.Generally speaking, Colonel Harold says, most of thecomplaints arise from local causes beyond the mains.The tank room offers great attractions as a play-ground on wet days and the household storage systemis a fertile source of pollution. In one case, wherea complaint was made that tap water was unfit fordispensing, inquiry revealed an aggregation of lead,shavings, and oakum left in the pipe by the

plumber. Evidently every consumer should demandof his landlord a tap direct off the main for drinkingpurposes. In periods of high atmospheric temperaturecomplaints of a disinfectant taste were sometimesreceived and later of an earthy taste at the time whena profuse growth of algae dies on the filter beds.But, all in all, London water is no mean beverage, andits palatability . may be largely attributed to itsmoderate hardness. During the year a committeeof residents in West Wickham, after wide investiga-tion, concluded that whilst it would be possible fortheir water to be softened, that would on balancebe no advantage to the community.

OZONE OR CHLORINE

But the scientific interest of the present report isgreatest in the big issue which will soon have to bedecided as to the choice of the final disinfecting agentin water purification. The drought brought to lightdefects in the filtration system as a result of whichchlorine and ammonia points have been installedin many places as an additional safeguard. Thecontinuous flow of water through storage systemsresults in an enormous reduction of the bacterialand organic content of the water. Next comes anefficient filter barrier, and finally a chemical processwhich needs time for effective action either in contacttanks or in the mains before the draw off. The aimof successful water practice is to supply a worked-out weathered water with a composition like the

unpolluted natural water, and in contradistinctionto campaigning measures chemicals are used onlyas a finishing process and as a corrective to counteran emergency. The importance of such an invulner-able barrier is illustrated by an incident at Milwaukeein 1916, when the chlorine was accidentally shut offfor several hours and the water was badly pollutedfor one day. The result of this was 25,000 to 100,000cases of diarrhoea followed by about 500 cases of

typhoid fever with 60 deaths. The choice of finalprocess for London water rests between ozone andchlorine-or rather combinations of chlorine andammonia, for free chlorine is no longer used. Ozone

imparts an excellent finish to water and removes themajority of disagreeable tastes. When it has doneits work it leaves nothing behind but oxygen. Awater cannot be overdosed with ozone, since the gasis ultimately dissipated. Ozone is increasinglypopular in France and has been tried out at one ofthe Board’s works at Barn Elms. But whereaschloramine continues to function as an efficient

germicide under the worst possible conditions,ozone requires a filtrate of fairly uniform quality.On the other hand, with ozone the contact period

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need be only a few minutes, in contrast with the oneand a half to two hours contact required in the tankafter a standard dose of ammonia and chlorine. Butthen again the longer contact period may provide,and not infrequently does, a completely sterile water.There is a further suggestion, which requires carefulexamination, that ozonised water after exhaustionof the ozone becomes more susceptible to bacterialgrowth. Colonel Harold sums up the situation thus.From the consumer’s point of view, ozone presentsthe greater attraction, and if properly applied is aneffective sterilant, provided that at all times anabsence of breaches in the filter barrier can be

guaranteed. On the other hand, chloramine offers anall-round security under every possible condition andis the safety-first of waterworks practice.

AMERICAN PUBLIC HEALTH

ASSOCIATION

(FROM AN OCCASIONAL CORRESPONDENT)

MORE than two thousand fellows, members, andguests of this association were registered at theannual meeting held at Milwaukee, Wisconsin, fromOct. 7th to 10th. This is the largest attendancerecorded since a registration fee was inaugurated.

PoliomyelitisThe summer epidemic of poliomyelitis and the

resulting popular excitement had their effect uponthe programme. The governing council voted thecreation of a special committee to confer with theU.S. public health service and to announce to thepress and to the public whenever it may be necessarysuch dicta regarding the administrative control of

poliomyelitis as may be calculated to allay panicand quiet or prevent unreasonable agitation. As towhether there is any knowledge to disseminate adifference of opinion was expressed. The epidemio-logists state that we know at least as much aboutpoliomyelitis as about scarlet fever. An experiencedhealth officer retorts by saying that if every healthofficer died to-morrow there would be neither morenor less poliomyelitis as a result. Dr. James P.

Leake, senior surgeon U.S. public health service,made an effective plea for the reporting of paralysiswhenever it occurs. In North Carolina, where thisyear’s epidemic began (in April), 90 per cent. of thecases reported were paralytic. This is a quiteunusually high proportion. In New York, wherethere was an excess incidence though hardly anepidemic, 55 per cent. of the cases were paralytic.This summer gave occasion for the trial on a fairly

large scale of the vaccines prepared by Dr. Kolmerand Dr. Brodie. Dr. Kolmer’s vaccine is a livingattenuated virus. It was given to some 12,000persons, nine of whom subsequently developed polio-myelitis, eight of them with paralysis. Dr. Kolmeris convinced that in each case the disease was in thestage of incubation and developed because thevaccine was given too late to produce immunity.His critics, however, are not satisfied that there wasno causal relationship between vaccination andpathogenesis. They refuse to regard the livingvaccine as safe. Dr. Brodie’s vaccine prepared inthe laboratories of the New York City departmentof health is a killed vaccine. It has been given to8000 persons and one only has developed polio-myelitis. The vaccine given in this one case hadreceived three times the treatment needed to make

it non-infectious to monkeys and had in additionbeen shipped from New York to the west coast.The disease developed well within the period ofincubation from the date of known exposure. Criticsaccept the safety of Dr. Brodie’s vaccine, but con-sider further experience necessary to prove its

efficacy. So indeed does Dr. Brodie, who is refusing tosupply his vaccine except for properly controlledexperimentation.

Whooping-coughDr. Louis W. Sauer reported on results obtained

with his pertussis vaccine which is now being usedextensively by physicians in this country. Dr. Sauersees no evidence that pertussis vaccine has thera-peutic value. However, with vaccine prepared andadministered in the Evanston Hospital he had hadcomplete success in prophylaxis. With " authorised "

commercial vaccine the success has been less completeas is shown in the following Table.

Three-year Report on Pertussis Immunisation

Unsolicited reports have been received from58 physicians in 22 different States, the total figuresgiven being 6455 patients injected, 476 exposed, and 81failures. The high proportion of failures to exposuresand the low proportion of exposures to injected areexplained on the ground that many of these

physicians had no means of knowing of exposuresexcept in such cases as subsequently developed thedisease.Every attempt has been made to ensure that the

" authorised " commercial vaccine shall be preparedby exactly the same methods as those used in Dr.Sauer’s laboratory in Evanston. Three possiblecauses of failure were discussed : (1) The warming ofthe vaccine. At the Evanston Hospital this is notallowed to take place at any time between prepara-tion and administration. In distribution of com-mercial vaccine over the country uninterruptedrefrigeration has not been practicable. (2) Age ofadministration. Seven out of ten failures occurredin children over 3 years of age. As a result of thisobservation Dr. Sauer is now recommending thatchildren over 3 years receive a total dose of not lessthan 10 c.cm. (3) Use of recently isolated strains.In preparation of commercial vaccines there maybe difficulty in obtaining recently isolated strains.Microphotographs were displayed showing the markedchanges in morphology undergone by B. pertussisin culture.

Mental HygieneDr. Elizabeth I. Adamson, of the department of

psychiatry, Columbia University, made a strongpoint for the inclusion of this subject in official

public health programmes when she pointed out thatpsychogenic illness, like tuberculosis, is mainlyacquired in childhood and is a family disease com-municated by prolonged and repeated exposure.Prof. Grant Fleming, of McGill University, while