232 



NATURE 



\Jan. S, 1880 



of the locnl conditions which, if added to crowding, filth, 

 or other insanitary conditions and want of proper ventila- 

 tion, is that of all others which favours cholera. Such 

 are the principal theories of the disease as they are sup- 

 ported by fact and argument which appear convincing. 

 Europeans, Americans, and some authorities in India 

 maintain the contagious view, whilst high authorities in 

 India adhere to the opposite theory, and declare roundly 

 that the facts of cholera, in India at least, are altogether 

 opposed to the contagion theory. 



On the question of importation of cholera in the Punjab 

 epidemic (1S75-6) and its spread by human agency, Dr. 

 Bryden, in his report, p. 308 (1876, published 1878), says : 

 — " The assertion amounts to this. The Punjab is 

 divided into thirty-two districts. Cholera was introduced 

 into seventeen of these in 1875, and therefore it spread. 

 Cholera was not introduced into fifteen districts, and there- 

 fore did not appear, or, if it was introduced, influences of 

 which we know nothing stopped its propagation in these 

 districts. Unknown causes prevailing in the one-half of 

 the area are presumed to influence the human system so 

 that it is capable of receiving cholera, and in the other to 

 act universally as an antidote even to a cholera poison 

 when introduced. This is what is offered as antagonistic 

 to the theory which asserts that cholera is air-borne and 

 is as far-flying as are the limits of natural areas. Pri- 

 marily, these theories cannot be reconciled ; the one or the 

 other is false. If cholera is spread only by the human 

 being, the theory which shows it to be air-conveyed is 

 untrue ; if cholera is spread solely as an aerial miasm, 

 then the theory which recognises only the effects of human 

 intercourse is unfounded. The most that is admitted 

 by the advocates of the human theory is, that the subjec- 

 tion of cholera to meteorological agencies is absolute,and 

 that these influences can, and do operate so as to do away 

 altogether with the effects of thepoison, although imported. 

 They do not recognise the entity minus the human being. 

 The antagonistic theory, while holding, as opposed to 

 demonstrable fact, the statement that cholera moves only 

 by human agency, may, if necessary, be extended in its 

 scope so as to embrace the other ; that is to say, the 

 inquiry is left open as to whether or not the cholera entity, 

 after being aerially distributed, may be subsequently pro- 

 pagated or spiead by man. In the theory which 1 

 cholera solely with man there is no such exten 

 Human intercourse must explain every fact of spread and 

 propagation, and nothing is left to the play of natural 

 agencies. Human intercourse, giving the widest scope to 

 the signification of the term, cannot pretend to account 

 for any fundamental phenomenon displayed during the 

 progress of epidemic cholera ; and, therefore, I assert the 

 theory to be radically untrue as applied to the behaviour 

 of cholera in India. I do not say that the above state- 

 ment will hold true all over the world ; and, even as ap- 

 plied to India, the theory does not preclude the possibi- 

 lity that cholera may be conveyed by the human being. 

 Naturally the recoil is to the opposite extreme. The bold 

 statement that cholera is never spread over an area unless 

 human agency intervenes, is apt to be met by the equally 

 dogmatic statement that cholera is as pure a miasm as 

 malaria, and as little amenable to the control of man. 



In the present state of our knowledge we can only be 

 guided by the inferences from well-ascertained facts and 

 such laws as we have ascertained to be in constant 

 operation, watching and carefully observing until we 

 may, were it only by a process of exclusion, arrive at 

 some deeper knowledge still. "So far," says the chief 

 sanitary authority in India, "the history of cholera is full 

 of enigmas and seeming contradictions, and though we 

 have of late years collected many valuable data, and 

 understood the importance of studying them on a broad 

 basis, we know no more of the exact cause of the 

 disease than our grandfathers did. We know that, what- 

 ever the cause may be, it flourishes in the midst of 



insanitary conditions of dirt and overcrowding, and 

 especially of impure water, impure from whatever cause ; 

 we know that it is liable to occur under certain conditions, 

 and at certain times and seasons, and we should endeavour 

 to extend that knowledge, and hope, as we do so, to arrive 

 at the precise nature of the disease itself." But it may 

 be well to remember that ''expenditure of public money 

 must take place only on observed facts and experience," 

 not in accordance with theories. " It would be prejudicial 

 to real sanitary work if opinions which have been promul- 

 gated in some parts of India, as to the cause of cholera 

 being due solely to the state of the water-supply, were to 

 take root." 



It is most important that we should arrive at some 

 definite conclusion as to the real nature of the disease, 

 for it is impossible but that our conceptions on this subject 

 must influence the sanitary measures that deal with it, and 

 I believe the question must find its final solution in India, 

 where the disease is always present in its endemic and 

 seldom absent from the epidemic areas. The highest 

 authorities — for both I have the greatest respect — differ 

 toto C02I0 on this subject. Is it that they are both right, 

 though seemingly SO opposed in their views? Like the 

 knights who fought about the silver and golden sides of 

 the shield, will they not change places, and find why they 

 differed ? 



I would venture to suggest that in India the inquiry 

 might be pushed with more detail in regard to individual 

 cases and outbreaks in certain limited areas ; and that, on 

 the other hand, one or more epidemiologists of European 

 fame should be deputed to visit India and study cholera 

 with the eminent men who have devoted so many years 

 of close attention to it there. It might be, I believe it 

 would be, that mutually they would gain from each other, 

 and that those who went out would find their own views 

 confirmed as to the disease in Europe — modified as to 

 what they deemed it to be in India. Of one thing I am 

 convinced, that simple truth is the object of their search ; 

 and I feel sure that from such combined action the greatest 

 benefit would result. 



POPULAR NATURAL HISTORY* 



JUDGING by the continuous stream of popular 

 "Natural Histories," the demand for such books 

 must be great. Messrs. Cassell have already published 

 many volumes of the kind, some dealing with the whole 

 animal kingdom, some with a single class ; they are now 

 bringing out a series of volumes under the editorship of 

 Dr. Martin Duncan, and in the mean time they present 

 us with a single volume of a still more popular character 

 by Dr. Perceval Wright. This book, as we are told in the 

 preface, is intended for that large class of readers who, 

 while they take an intelligent interest in the study of 

 natural history, have but little taste for the technical 

 details which would naturally form the bulk of a scientific 

 manual on the subject. For this reason the space devoted 

 to the several orders is roughly proportioned to the 

 amount of interest generally felt in them. The mammalia 

 occupy more than a third of the volume, the remaining 

 orders of the vertebrata about an equal space, while the 

 whole of the invertebrates are compressed into the space 

 that remains— about one-fourth of that occupied by the 

 vertebrates. The author tells us that his aim has been 

 "to compile a story-book about animals, and at the same 

 time in some degree to write a scientific manual." This 

 is undoubtedly a difficult thing to do, and to do it 

 thoroughly and in the best style would be a fitting life- 

 work for a great naturalist. It would have to be done as 

 a labour of love, not to the order of a publisher ; and the 



' Animal Life : being a Series c f 1 >esci iptions of the Various Sub-kingdoms 

 of the Animal Kined m. By Perceval K. Wright, M.A., M.D., Sc., Pro- 

 fessor of Botany in the University of Dublin. With Illustrations. (Cassell, 

 Petter, Galpin, and Co., 1 ' ^' cw Voile.) 



