A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 



" To the solid ground 

 Of Nature liusts the mind -which builds for oyt'."— Wordsworth 



THURSDAY, NOVEMBER 5, 1885 



HYDROPHOBIA 



"fSpo<l>o0iav Grteci appellant : miserrimum genus morbi. 



ONCE more M. Pasteur is attracting tlie attention of 

 the civilised world by his brilliant investigations. 

 The disease which he hopes to prevent and ultimately to 

 erase from the records of human misery is happily rare, 

 but those who have watched it know that it is one of the 

 most terrible in its effects, and that it is incurable by any 

 means at present known. So strange are its symptoms 

 and ' its course, that it has been asserted to be no 

 real malady but a mere result of fright and superstition.' 

 But of its reality there is unhappily no room for serious 

 question. 



It never arises of itself. Like small-pox and syphilis, 

 it is always the result of contagion, and the method and 

 conditions of its transference from rabid dogs or other 

 animals to man are well known. Hitherto the only 

 chance, when a human being has been bitten by a mad 

 dog, has been to remove or isolate or destroy the virus 

 by suction, or ligature, or cautery. And it has been 

 doubted whether these methods are really successful even 

 when the disease does not manifest itself afterwards. 

 For there is often reasonable doubt as to the nature of 

 the disease in the biter. All vicious dogs are not " mad," 

 and all mad dogs are not truly rabid. And when, as 

 often happens, the dog has been at once destroyed, it is 

 impossible to supply deficiencies of previous observation. 

 Moreover, when bitten by a rabid dog, the sufferer may 

 yet escape, for the teeth may only have grazed the skin, 

 and not penetrated to the living tissues beneath, or the 

 poisonous saliva may have been mechanically wiped off 

 by the clothing which the teeth have pierced. As with 

 the venom of snakes, so with the saliva of rabid dogs : it 

 is not enough for it to be spread over the skin, for that 

 will not absorb it, nor even to be swallowed and taken 

 into the stomach, for there, as physiologists say, it is still 

 "outside the body," and, before it can be absorbed 



' So, in the last century, Sir Isaac Pennington, Regius Professor of Physic 

 at Cambridge, and in recent times Prof. Mashka, of Prague. 



Vol. xxxiii. — No. 836 



undergoes such changes by the process of digestion, as 

 kill the germs or decompose the chemical compound. 

 The virus must be introduced into the living tissues 

 before it can be carried over the whole body by the 

 channels of the lymph and blood, and reach the central 

 nervous system, on which it exerts its characteristic 

 poisonous action. But, when once so introduced, there is 

 every reason to believe that the terrible effects are 

 constant and uniform. The state of the receiver of the 

 venom at the time may probably modify the rapidity of 

 absorption, as is the case with stimulants and with 

 poisonous drugs ; but so far as we know there is no 

 power in the most healthy organism by which the subtle 

 venom, once absorbed, can be neutralised or thrown out. 

 The methods above mentioned ' — suction by the mouth or 

 by cupping glasses, ligature, and caustics or the actual 

 cautery — all aim at getting the poison out before it has 

 been absorbed. Often they come too late, often they 

 are impracticable or ineffectual from the first. However 

 long the time of " incubation " may be, the interval 

 between the reception of the virus and its spread over the 

 body, no method of preventing the terrible result is 

 known. The length of incubation is far longer than it 

 is in the case of small-pox, of cow-pox, of syphilis, and 

 other known contagions. In two-thirds of the cases col- 

 lected by Prof. Bollinger, of Munich, the interval of 

 incubation was under two months ; and probably it never 

 extends to so long a period as was formerly supposed. 

 The length of this period makes it almost certain that we 

 have to do, not with a mere chemical compound, as in the 

 case of subcutaneous injection of morphia, and probably 

 of the cobra-poison, but with a " particulate contagium," 

 like that of small-pox and chicken-pox, with a living and 

 growing organism, like those of relapsing fever and of 

 anthrax. 



Whatever the conclusions to which pathologists will at 

 last be led on these points, the important fact remains 

 that there is an interval of days or months in which the 

 latent plague, established in the patient's body, but not 

 yet ripe for mischief, may be attacked. 



^ These are what were known to the ancients :— " Si rabiosus canis est. 

 cucurbitula virus ejus extrahendum est. Deinde . . . vulnus adurendum 

 est." Celsus de Medicina, lib. v. cap. xxvii. § 2. 



