366 



NA TURE 



[August 20, 1891 



ever been so in the course of scientific progress, that in the 

 enthusiasm of research, which is rewarded by such brilliant 

 results, early generalization has too often been followed by 

 disappointment, and it may be by temporary discouragement of 

 hopes which seemed so promising. 



It would be well to bear in mind a caution recently given by 

 the Duke of Argyll, " that we should be awake to the retarding 

 effect of a superstitious dependence on the authority of great 

 men, and to the constant liability of even the greatest observers 

 to found fallacious generalizations on a few selected facts" 

 {Nineteenth Centtny, April 1891). Still, it is in the region of 

 scientific research by experiment that we look for real progress, 

 and we can only deplore the mistaken sentiment, the false esti- 

 mate, and the misconstruction of its aspirations and purposes, 

 which have placed an embargo on experiment on living animals, 

 rendering the pursuit of knowledge in this direction well nigh im- 

 possible, if not criminal ; whilst for any other purpose, whether 

 of food, clothing, ornament, or sport, a thousandfold the pain 

 may be inflicted without question. The inconsistency of the 

 sentiment which finds unwarrantable suffering in an operation 

 performed on a rabbit, when the object is to preserve human or 

 animal life or prevent suflfering, but which raises no objection to 

 the same animal being slowly tortured to death in a trap, or 

 hunted or worried by a dog, needs no comment ; whilst the 

 spirit which withholds from the man of science what it rtadily 

 concedes to the hunter is, to say the least, as much to be 

 regretted as it is to be deprecated. 



It must be remembered that, important as are the researches 

 into microbiology, there are other factors to reckon with before 

 we can hope to gain a knowledge of the ultimate causation of 

 disease. It is not by any one path, however closely or carefully 

 it may be followed, that we shall arrive at a full comprehension 

 of all that is concerned in its etiology and prevention, for there 

 are many conditions, dynamical and material, around and wi'hin 

 us which have to be considered in their mutual relations and 

 bearings before we can hope to do so ; still, I believe we may 

 feel satisfied that the causes of disease are now being more 

 thoroughly sought out than they ever have been — all honour to 

 those who are prosecuting the research so vigorously — and that 

 though individual predilection may seem sometimes to dwell too 

 exclusively on specific objects, yet the tendency is to investigate 

 everything that bears upon the subject, and to emphasize all 

 that is implied in the aphorism, Sahis populi, suprema lex. 



The morning sitting of the Section and most of the afternoon 

 sitting was devoted to papers and a discussion on " The Mode of 

 preventing the Spread of Epidemic Disease from one Country to 

 another." 



The chair was occupied successively by the President, Pro- 

 fesseiirBrouardel ol Paris, and Prof, da Silva Amado of Lisbon. 



Surgeon-General Cuningham, of London, cpened the dis- 

 cussion, and said the n.ode.s of prevention of spread of disease 

 from one country to another were three in number, (i) quaran- 

 tine, (2) medical inspection, (3) sanitary improvements. In his 

 remarks he dealt chiefly with cholera, and he held that the chief 

 factor of cholera, being carried by atmospheric currents, cannot 

 be excluded from any country, and where it has been distributed 

 over any area it excites the disease directly in many persons 

 who are predisposed to it, and forms foci of it whenever it finds 

 localities suitable for its increase ; these are often very 

 limited in extent, not embracing more than a single house, 

 or even a portion of a house, or ship ; the mortality among 

 the steerage passengers in the latter is often very great, 

 while the cabin passengers and all the crew have scarcely 

 a case. Such foci are always badly ventilated, and the 

 emanations arising in them acquire much greater density 

 than in the open air; as a natural consequence the cloth- 

 ing of those who reside in them absorbs an amount of the 

 emanation sufficient to produce cholera in susceptible persons 

 outside uritil it has 1 een dissipated by exposure ; those so 

 affected, however, and the others who have contracted the com- 

 plaint apart from such foci, do not seem to have any such 

 mfluence, it being not the body but the emanations from the 

 locality which generate the disease. Cholera, tlierefore, cannot 

 be excluded f-om any country by general quarantine. All that 

 can be done is by hygienic measures to improve the health of 

 the population, and to remove the conditions which favour the 

 formation of foci. The placing ships which arrive with cholera 

 on board under observation, removing their crews and passen- 

 gers to suitable localities on shore until the disease ceases among 



them, are very proper precautions, and may prevent a small 

 amount of the disease among the surrounding population, but 

 can never prevent an epidemic if the necessary factors be in 

 progress. 



Inspector- General Lawson then followed with a paper 

 on "The Communicability of Cholera from one Country to 

 another." 



To draw up a plan to prevent the extension of a disease, say 

 cholera, from one country to another, with any prospect of 

 success, it is necessary to have a general acquaintance at least 

 with the different factors which contribute to the result, and of 

 their mode of operation. The existing- information on these 

 points falls far short of these requirements, and its increase has 

 been enormously impeded by the belief that man himself is the 

 chief agent in diffusing the disease ; and by interpreting the 

 evidence obtained from various sources with an undue bias in 

 favour of the theory. There has been, in short, and still remains, 

 a most serious error in assuming that personal communication is 

 the principal factor ; and a no less extensive error in the methods 

 and reasoning by which the central idea of diffusion by man was^ 

 advocated. 



The character and causes of cholera must be derived from a 

 critical examination of all the evidence Nature presents, and from 

 a study of the methods she herself adopts, instead of from our 

 a priori deductions. Cholera occurs in two different forms : 

 simple cholera or cholera nostras, of little severity, and attributed 

 to local causes ; and Asiatic epidemic, or malignant cholera, 

 always a serious disease, and by many attributed to a poison 

 given off by those labouring under it to others, and so diffused 

 until it becomes epidemic. 



Since 1832, when cholera visited Europe in the epidemic 

 form, cholera nostras has been observed to fluctuate every few 

 years, and with the milder cases occur a certain number present- 

 ing all the characters of the malignant disease ; these cases occur 

 singly or in small groups, hut in every instance they accompany 

 epidemics of varying severity, at no very great distance off, and 

 are under the same "epidemic influence." 



Those who support the theory that man diffuses cholera are, 

 necessarily, required to show that persons under the disease 

 must arrive at points where it has not yet appeared, before it 

 coirimences in these latter, and that the first attacks in the new 

 locality have been in persons exposed to the imported cases : 

 but there are now a good many instances of epidemics springing 



in localities at a distance from where the disease was 



already prevailing, and wiihout any trace of importation, 

 and where those first attacked had resided in the country for 

 many months in succession without communication with any 

 previous case. Such were the outbreaks at Southampton in 

 1865, at New Orleans in 1873, and at Toulon and the south of 

 I France in 1884, all of which were most carefully investigated 

 on the spot. The only other conclusion open was that the 

 necessary factors were supplied by epidemic influence ; and if 

 supplied in one instance, supplied in all : where there appeared 

 to have been importation at the commencement of the outbreak, 

 it must not be assumed that the disease was communicated by man 

 unless the epidemic influence could be excluded, as at present it 

 could not. It seemed probable that the exciting factors were 

 conveyed by the air, whether fully or only partially developed, 

 and consequently it was not in our power to exclude them ; but 

 much might be done by hygienic and other local means to limit 

 their development in the localities they reached, and so to avoid 

 excessive mortality. 



Dr. Ashburton Thompson, official delegate of the Govern- 

 ment of New South Wales, followed with a paper entitled 

 " Quarantine in Australasia : Theory and Practice." He said 

 that the amount of traffic which had to be dealt with was an 

 important consideration in all questions of practical quarantine. 

 The Australasian Sanitary Conference of Sydney, N.S.W., 

 1884, was attended by delegates of each of the six Governments, 

 and by the speaker. Their resolutions were unanimous, ac- 

 cepted by each Government, and presented to each Parliament. 

 They had not been modified since 1884, and were therefore 

 those received in Ausi ralasia at the present day. Limited quaran- 

 tine, medical inspection, the outcome of England's local condi- 

 tions, was exactly suited to them, but not necessarily suitable, 

 therefore, where local conditions differed from England's. The 

 first proposition of the Conference was that the degree of protec- 

 tion which qtiarantine measures can afford varies inversely with 

 the ease of communication between the infected coimtry and the 

 country to be defended. The difference between English and 



NO. II 38, VOL, 44] 



