NA TURE 



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THURSDAY, FEBRUARY ii, 1886 



PRECAUTIONS AGAINST HYDROPHOBIA 



THE frequency of the terrible and incurable disease 

 known as hydrophobia has led to precautions being 

 adopted in London, which, if universally carried out, 

 would probably rid us of the plague. 



The recent progress of scientific pathology, i.e. of 

 medical knowledge which advances by the methods of 

 observation and experiment — has made clear much which 

 was previously obscured by traditional fables. 



It is now certain that hydrophobia is a real disease, not 

 the mere result of fright, not primirily a mental disorder 

 at all, but a definite sequence of bodily symptoms. Even 

 its anatomy has been investigated by the beautiful 

 methods of modern microscopical research ; and the coin- 

 cidence of the results obtained by skilled histologists, 

 working independently, makes it probable that the lesions 

 discovered are essential and not accidental. If so, the 

 anatomical part of the disease consists in a perivascular 

 inflammation of the central nervous system, and par- 

 ticularly of the part known as the " bulb," or medulla 

 oblongata, which is situated between the spinal marrow 

 and the brain. Moreover, it has been ascertained that 

 hydrophobia belongs to the group of " specific," or, as 

 they were termed by the late Registrar-General, "zymo- 

 tic," diseases, which always arise by contagion, and 

 always " breed true." It is most improbable that it ever 

 appears, either in man or animals, spontaneously or from 

 common causes. In men and in brutes alike it fol- 

 lows the bite of a rabid dog, or other animal. How it 

 first arose, and whether in dogs, wolves, foxes, cats, 

 badgers, or in Carnivora before they were differentiated 

 into the three groups of cats, dogs, and bears, with their 

 several allied kinds — is quite unknown. But we have no 

 historical knowledge of the origin of small-pox or measles, 

 or even of diseases once thought to be unknown before 

 modern times, such as syphilis, diphtheria, and cholera. 

 The evolution of diseases, like that of the human beings 

 and the brute creation they infest, is matter of speculation 

 only. 



Now there are three ways of dealing with these specific 

 diseases. One is by treatment when they are fully deve- 

 loped. This is the business of the physician, and in 

 many of them his treatment is so far elTectual that, 

 though prevention would be better than cure, yet cure is 

 generally the result of rational treatment. But no effec- 

 tual treatment of hydrophobia is known. In spite of the 

 pretensions of charlatans and the constant attempts of 

 physicians, no plan of treatment has yet been discovered 

 which can show a single instance of success. 



The second method is to arm the domain of life against 

 an invading pest beforehand, instead of driving it out 

 when already an entrance has been gained. This is the 

 method first applied to small-pox by inoculation with 

 imperfect success, and afterwards far more efficiently by 

 Jenner's discovery of vaccination. No corresponding 

 process of protection against other human diseases had 

 been discovered until Pasteur's recent attempts to apply 

 the principle to hydrophobia; but the same eminent J'i'?r'<?/// 

 Vol. xxxiii.— No. 850 



had before devised similar inoculations to prevent more 

 than one epidemic disease peculiar to domestic animals. 

 We referred in a previous number to his system of 

 inoculation as a preservative against hydrophobia, and 

 since then the cases on which he has operated have 

 multiplied. One difficulty of judging as to the efficacy 

 of his method is that not more than half the persons bitten 

 by rabid dogs develop hydrophobia ; the poisonous saliva 

 may have been wiped off the teeth by the clothing as it 

 was penetrated, or the effusion of blood may have imme- 

 diately washed it away, or some local application may 

 have destroyed it. Another is that hydrophobia has 

 such an uncertain and often protracted period of " incuba- 

 tion," more uncertain and more protracted than that of 

 any other specific disease, varying from a few weeks, or 

 ,-ven possibly a few days, up to eleven or twelve months, 

 ana in some rare cases reaching two years, or possibly a 

 longer period. But now that Pasteur's inoculations have 

 considerably exceeded a hundred in number, these sources 

 of fallacy are more likely to be eliminated, and as the mass 

 of evidence increases, and the time grows longer, a con- 

 clusion one way or the other will become inevitable. 



There is, however, a third method of dealing with hydro- 

 phobia, independent of future possible treatment and of 

 inoculation. It is what the late Sir James Simpson 

 called " stamping out " the infection in the case of cattle- 

 plague. If we could kill every rabid dog and wild animal 

 throughout the world at once, we have reason to believe 

 that hydrophobia would become of only historical interest. 

 Happily it has never (so far as we know) been transmitted 

 from one human being to another, so that it would not be 

 necessary even to await the death of the victims already 

 bitten before feeling secure. Destroy the disease in 

 animals, and it would perish from among men. 



But since the infection takes place in the great majority 

 of cases by means of a dog's bite, it would be sufficient to 

 prevent every rabid dog from biting. This of course is 

 impossible : but if we could make a dog's bite a very 

 rare instead of a very common occurrence, the chance of 

 being bitten by a rabid dog would become indefinitely 

 remote. If we could prevent dogs from biting one 

 another, hydrophobia would cease from among dogs also. 

 The rabid dogs would die innocuous. It has been pro- 

 posed to draw the large canine teeth, but this would not 

 entirely prevent dangerous bites, it could never be carried 

 out thoroughly, it would give needless pain to intelligent 

 animals, and in attempting to enforce it more bites would 

 probably be inflicted on the operators than if the dogs 

 had been let alone. 



The only rational methods yet proposed of preventing, 

 or rather of reducing, the number of dog-bites is first to 

 diminish the number of dogs by imposing a higher tax 

 on those kept as domestic animals, and by destroying 

 ownerless, miserable, and.half-starved curs ; and secondly 

 to prevent dogs biting when abroad by enforcing the use 

 of muzzles. These may be constructed so as not to in;er- 

 fere with the animal breathing, perspiring, and even 

 drinking with comfort, and yet to prevent his using his 

 teeth. 



Such muzzles are enforced and worn by a recent regu- 

 lation of the Metropolitan Police, and troublesome as 

 such interference with individual liberty (whether of dogs 

 or their masters) is felt to be ;in this country, it may be 



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