567

rates for sanitary purposes the cubic capacity of a houseshould be considered, but the garden ought not to be con-sidered, for a garden was a sanitary gain to the whole

community.

REPORT OF THE INDIAN PLAGUE COM-MISSION UPON HAFFKINE’S ANTI-

PLAGUE INOCULATION.

WE have received from the Under Secretary of State forIndia a copy of the fourth chapter of the forthcoming Reportof the Indian Plague Commission. This chapter has beenissued in anticipation of the publication of the completeReport, in recognition of the practical importance of the

subject with which it deals. The chapter in question, whichcovers some 87 pages of foolscap size, is devoted solely to aconsideration of Mr. Haffkine’s method of prophylacticinoculations, or, as they are termed in the report, anti-plague inoculations."

It is impossible to sum up in a few words the veryextensive ground which this chapter covers. It may besaid, however, that it is mainly a close but lucid criticismof a large mass of material, statistical and otherwise,which was placed before the members of the Commission inmany different parts of India; that this is supplemented bythe results of certain special observations and experimentsmade by the members of the Commission themselves or

undertaken by others at their request ; and that it ends witha number of definite conclusions and recommendations towhich the consideration of this material naturally leads.It is to the latter that most readers will probably look first,and by that very large body of persons in this countrywho have been awaiting a definite " yes or "no" "verdict as to the value of Mr. Haffkine’s method theanswer required will be found in the last paragraphof this chapter of the report. " We cannot," that paragraphruns, "bring to a conclusion this consideration of anti-

plague inoculation by Mr. Haffkine’s prophylactic fluidwithout expressing our sense of the importance of themethod which Mr. Haffkine has devised and of the resultswhich have been achieved by it. The credit due to Mr.Haffkine is the greater because the difficulties with whichhe had to contend in this matter could only have been over-come by great zeal and endurance. Mr. Haffkine’s work onanti-plague inoculation, while not based on any new scien-tific principle, constitutes, it seems to us, a greatpractical achievement in the region of preventive medi-cine." From these remarks it will be seen that, in

general terms, the value of the method of prophylaxis inquestion is fully endorsed by the Indian Plague Commission.Notwithstanding the severe and searching criticism to whichthe method and the results claimed for it are subjected,and in spite of certain obvious defects in both (which arepointed out in detail in this chapter), the Commissionersconsider Mr. Haffkine to have performed a great life-savingwork in the face of almost insuperable difficulties.The principal conclusions of the Commission in regard to

the prophylactic naturally group themselves into twodivisions : firstly, those concerned with the protective effectof the inoculations upon individuals and communities ; and,secondly, those concerned with the feasibility of adopting ageneral policy of inoculation as a practical measure againstthe ravages of plague. We quote in full the conclusionsarrived at under each of these heads.

Firstly, in regard to the protective value of the pro-phylactic inoculations the Commission summarise theirconclusions as follows:-

I. Inoculation sensibly diminishes the incidence of plague attackson the inoculated population, but the protection which is affordedagainst attacks is not absolute. On the one hand, plague has attackedpersons who have undergone inoculation as many as four times in thecourse of two years previous to their attack. On the other hand, asmany as 8 per cent. of the inoculated population may suffer fromplague, as was the case in Bulsar. Many varying influences have beenat work in determining the rate of attack in different places, and it isimpossible to give a numerical expression for the measure of protectionagainst attack which inoculation confers.

II. Inoculation diminishes the death-rate among the inoculatedpopulation. This is due not only to the fact that the rate of attack isliminished, but also to the fact that the fatality of attacks is dimi-nished. Here, again, no numerical expression for the amount by whichthe leath-rate is diminished can be given.

III. Inoculation does not appear to confer any great degree of pro-tection within the first few days after the inoculation has been per-formed. This fact., we mav note in passing, has an important bearingon the risk of infection which would be incurred by recently inoculatedpersons if they were left behind in surroundings so plague-infected asto render their evacuation by the uninoeulated desirable.

IV. Inoculation confers a protection which certainly lasts for someconsiderable number of weeks. It is possible that the protection lastsfor a number of months. The maximum duration of protection canonly be determined by further observation.V. The varying strength of the vaccine employed has apparently

had a great effect upon the results which have been obtained frominoculation. There appear3 to be a definite quantum of vaccinatingmaterial which gives the maximum amount of protection; and pro-vided that this quantum can be injected in one dose, and providedalso that the protection turns out to be a lasting one, re-inoculationmight with advantage be dispensed with. The best results of inocula-tion will only be obtained after an accurate method of standardisationhas been devised.

Secondly, in regard to the feasibility of adopting inocula-tion as a general plague measure the Commission formulatethe following conclusions :-

1. Experience gained hitherto has shown that it is very seldompossible to get a large proportion of the inhabitants of an uninfectedplace inoculated.

2. It has been possible,-where the inducement of exemption fromsegregation and eviction has been offered, to get a large proportion ofthe inhabitants of an infected place inoculated quickly.

3. It has been possible in one place, Mysore city, even where noinducement that touched the great mass of the people could beoffered, to get a considerable proportion of the inhabitants of aninfected place inoculated quickly.

4. It has been possible, also, to induce a large proportion of particularcommunities, such as the Khojas of Bombay and Karachi, to be inocu-lated under the influence of their leaders.

The recommendations based upon these conclusions, andon the additional " consideration that it is advisable to makethe operation as effective as possible, as little inconvenientas possible to the person inoculated, and as easily carried outas possible by the inoculator," are as follows:-

I. We have already insisted on the necessity for the accuratestandardisation of the vaccine, as being essential to the attainment ofthe best results, both as to the protection conferred and as to theduration of that protection. We have pointed out, also, that the intro-duction of an accurate system of standardisation may possibly obviatethe necessity of employing two successive inoculations.

II. With a view to dispelling the natural fears of the people, andavoiding all unnecessary risk to the inoculated, and further, with aview to enabling the inoculations to be carried on with the leastpossible amount of attendant inconvenience, we would insist upon thenecessity that stringent precautions should be taken to ensure that allthe vaccine used is quite free from contamination, and we would recom-mend that the volume of the necessary dose should be made as smallas possible.III. With a view to removing any possible ground for distrust as to the

conveyance of disease by inoculation from one person to another wewould recommend that the syringe should be sterilised in the presenceof the person about to be inoculated.

IV. We are of opinion that inoculations under the safeguards andconditions stated above should be encouraged wherever possible, and inparticular it seems to us desirable to encourage inoculation among dis-infecting staffs and the attendants of plague hospitals.

Although occupying the last pages of the section of thereport now issued we have quoted these conclusions andrecommendations near the commencement of this notice forthe reasons already stated. For the present we leave themwithout comment and may proceed to discuss briefly the largermass of subordinate and detailed conclusions arrived at inthe body of the report, upon which the main conclusions andrecommendations just quoted are based.The section of the report now issued opens with a brief

résumé of the history of preventive inoculation from thediscovery of small-pox inoculation down through thediscovery of vaccination, the work of Pasteur uponanthrax, that of Ferran upon cholera, and themore recent work of Haffkine himself upon the last-named disease before he took up the subject of plagueprophylaxis. It is unnecessary here to dwell upon thispreliminary review of what is familiar to most readers whohave any acquaintance at all with the history of preventivemedicine. Coming to the subject of inoculation againstplague it is pointed out that the first experiments in thisdirection were those of Yersin, Calmette, and Borrel, whoin 1895 made a number of comparatively successful experi-ments on the production of immunity against plague inrabbits and guinea-pigs by the hypodermic injection ofdead cultures of plague bacilli. It was left to Mr.Haffkine to apply successfully a similar method on a largescale to the prevention of plague in human beings.The method followed by him is conveniently discussed

under the following different headings :-I. The method of preparing mass cultures of the plague bacillus.II. The method of controlling the purity or those cultures.III. The method of killing the plague bacilli with the view of con-

verting the culture into an immunising material.

568

IV. The method of decanting and bottling the prophylactic fluid.V. The method of ascertaining that the vaccine is free from con-

taminating micro-organisms and the precautions which are adopted forpreventing the growth of such organisms.VI. The method of standardising the vaccine.VI I. The composition of the vaccine.VIII. The volume of the prescribed dose.

As to the mode of preparing the mass cultures, the reportexpresses full approval of the methods adopted to avoid theuse of such animal products as might be offensive to the

feelings of the natives of India, and at the same time toproduce a growth in mass on a liquid substratum and toprovide for the efficient aeration of the cultures. Approval isalso, on the whole, expressed of the second point under con-sideration-the method of controlling the purity of the

cultures-though at the same time it is pointed out that torely solely upon " the specular appearance of the colonies ofplague bacilli, seen from behind by the reflected light throughthe depth of the agar," which is the method hithertoadopted, is one which, in less experienced hands than thoseof Mr. Haffkine, could scarcely be regarded as a trustworthyindex of the purity of the culture.The method of killing the cultures of plague bacilli

hitherto practised-by subjecting them to a temperature of65° C. for one hour-is also fully approved as being theroutine method adopted by every bacteriologist for a similarobject. It is, however, pointed out that Mr. Haffkine hasmade no experiments upon the effect of this heat, or uponthe effect of the addition of -2L per cent. of carbolic acid aspractised by him, upon the immunising powers of the fluid.The German Plague Commission has, however, shown thatas regards the bacterial sediment in the prophylacticfluid its immunising powers are in no way diminishedby the heating process, and the authors of the presentreport themselves have proved by experiment that the sameis true of the supernatant fluid. The curious fact is addedthat the experiments of the German Plague Commission I,showed that the addition of 2 per cent. carbolic acid had noeffect upon the immunising powers of a heated plagueculture, although it completely destroyed these powers in anunheated culture. No explanation of this curious fact isoffered nor is any attempt made to determine itssignificance.The methods of decanting and bottling the fluid and of

securing its sterility are naturally discussed’ at considerablelength. The mode hitherto adopted-of storing the fluid inordinary medicine-bottles closed by corks and sealed withsealing-wax-is one which obviously pre-ents very great diffi-culties in ensuring sterility, and in spite of various methods ofsterilising the bottles, the corks, and the syphon, the processof syphoning off an organic fluid such as the plague pro-phylactic from flasks into bottles cannot, it is found, beaccomplished without admitting, in a certain proportion ofinstances, outside contaminations. It will be recalled thatColonel Lawrie, I.M.S., of Hyderabad, went so far as tocondemn, in most unmeasured language, the entire use ofthe prophylactic in consequence of the contamination of acertain proportion of bottles. The members of the PlagueCommission are more moderate in their criticism. They-discovered by a series of accurate experiments that in some22 5 per cent. of bottles contaminations are present. These.are, in their opinion, due partly (but not " almost entirely,"as Mr. Haffkine urged) to imperfections in the sealing of thebottles and partly to the method of syphoning off the fluidfrom the flasks into the bottles. They, further, while ’,urging the necessity for devising some method which shallensure the absence of such contaminations, fully admit that, from a practical point of view, the presence of these con- Itaminations has never been shown to have such harmful

iresults as might be, and have been, urged against them ona priori grounds. "We have not," they say, "had any I,evidence laid before us which goes to show that any seriousill consequences have resulted from the defect in sterility ,,which was spoken of above. We made careful inquiries into ’,,this question in the various centres where anti-plague vacci-nations have been performed. In the overwhelming majorityof cases no evidence was adduced to show that anyinjurious effects had supervened upon inoculation. In afew isolated cases, however, there was evidence thatabscesses had occurred in the vaccinated at the seat of

injection." It is added, however, that it is impossible toassert that such abscesses, or an occasional long-continuedreaction at the seat of inoculation and continuance of fever,were in truth due to these contaminations and were notmerely toxic effects.

The method of standardising the prophylactic hitherto inuse has been of a very simple, not to say primitive, character.It has consisted in holding one finger behind the flask con-taining the fluid and judging by the degree of opacitypresent whether the fluid was of ordinary strength, andtherefore to be administered in the standard doses of two anda half cubic centimetres or of such strength as to be ad-ministered in fractions or multiples of that dose. In otherwords, a rough estimate of the amount of sediment (ordead bacilli) present has been taken as an estimateof the immunising powers of the fluid. A second methodof estimating its powers has been by observing itseffects upon the first 10 or 20 patients inoculated, thestrength aimed at being such as to produce an averagetemperature in the persons inoculated of 102° F. Thedifficulties and objections in the way of both these methodsare very obvious, and it is not surprising that the Commissiondwell on the imperfections of both methods. The difficultiesin the way. of standardising a fluid of the kind and ofobtaining an accurate dose of the immunising material areindeed exceedingly great. No systematic method, it is

pointed out, has been hitherto practised for ascertaining thevirulence of the cultures originally employed for theproduction of the prophylactic. Further, it is shownthat, while the sediment contains the great bulk,if not the entirety, of the immunising material, the super-natant fluid may in some instances contain a considerableamount of toxins. Where very large doses of a particularsample of the prophylactic are recommended there can be nocertainty that a dangerous dose of these toxins may not beintroduced. No attempt, it is also pointed out, has hithertobeen made to ascertain the weight of the sediment, or deadbodies of bacilli, injected in a given dose ; and in view ofthese considerations the members of the Commission arecompelled to state that they " cannot but take a serious viewof the fact that in a case like the present, where the esti-mation of the virulence was neglected, the weight of thebacterial sediment in a prescribed dose was in some samplesof the vaccine seven times as large as in other samples."

It is obvious from these statements that much yet remainsto be done before the practice of inoculation with a fluid ofthis nature shall fulfil all the conditions which soundscientific reasoning rightly demands of it. For the present—and this in itself is no small achievement-the method mayjustly claim to be a practical success and very nearly, ifnot quite, to attain to the high ideal of a certain and safeprophylaxis against one of the most deadly of all diseases.It is, moreover, founded upon a strict scientific basis, thoughit is clearly in many and important details open to the

charge of imperfection and empiricism. Time will doubtlessremedy these defects, and it is certainly regrettable that themembers of the Commission have contented themselves withmerely pointing out these imperfections and the necessityfor overcoming them and have not, with some minor excep-tions, made any definite suggestions or recommendations asto the manner in which they should be overcome.The statistics of the inoculations in various centres under-

go strict investigation. The principal observations uponthe effect of the inoculations have been made in Bombay,Daman, Lanauli, Kirki, Undhera, Hubli, Dharwar, Gadag-Betigeri, Bangalore, Karachi, Bulsar, Belgaum, and someother towns and villages. For the present we must contentourselves with this enumeration of places and with the briefstatement that, while the criticism of the evidence broughtforward in each of these places is largely of the nature ofan academic discussion of statistical material, it ends inalmost every instance with a free admission that the inocula-tions did largely reduce the mortality in the given place. Tothese criticisms and to the objections urged against Mr.Haffkine’s method of expressing numerically the reductionin mortality brought about by the inoculations we may,perhaps, refer on a future occasion.

VITAL STATISTICS.

HEALTH OF ENGLISH TOWNS.

IN 33 of the largest English towns 6079 births and5750 deaths were registered during the week endingFeb. 17th. The annual rate of mortality in these towns,which had been 21-2 and 22’7 per 1000 in the two pre-ceding weeks, further rose to 25’8 last week. In London