628 THE POPULAR SCIENCE MONTHLY. 



giving signs of illness in them. In 1854, for example, a young lawyer 

 went from Munich to Darmstadt, where his father resided. Up to that 

 time the father had never lived out of Darmstadt, and Darmstadt was 

 as free from cholera as Hampstead, and the distance from Munich was 

 much greater than Hampstead from Broad Street. The lawyer was as 

 well in health as Mr. Eley had been, but the lawyer's father fell ill 

 and died of cholera. There was no other factor in the case than the 

 return of the son from Munich. Darmstadt enjoyed an immunity from 

 cholera as great as that of Lyons, Versailles, Stuttgart, and many 

 other large cities. In 1854 a workman went home from the Exhibi- 

 tion of Munich to Darmstadt, where he fell ill and died of cholera 

 without the disease being spread to any other house, and no means for 

 disinfection or isolation had been adopted. In 1866 Prussian troops 

 were quartered in Darmstadt, and brought the cholera with them. 

 About thirty of the soldiers became ill with cholera, and many of 

 them succumbed ; again, none of the inhabitants of Darmstadt had 

 the disease. It must be admitted that Mrs. Eley might have been in- 

 fected through the intercommunication of her son, just as the lawyer's 

 father had been, without the intervention of drinking-water. The 

 argument in favor of the drinking-water theory rests on the fact that 

 the cholera ceased when the supply of water was cut off ; but no notice 

 was taken of the great majority of cases in which the water-springs 

 were not closed, and the supply of water not cut off, and yet the epi- 

 demics came to an end. Again, in Broad Street the pump-handle was 

 not taken off till September 8th. Now, an examination of the facts 

 will show that the cholera was already subsiding. In Broad Street, on 

 August 31st, there were thirty-one cases of cholera ; on September 1st, 

 one hundred and thirty-one cases ; on the 2d, one hundred and twenty- 

 five ; on the 3d, fifty-eight ; on the 4th, fifty-two ; on the 5th, twenty- 

 six ; on the 6th, twenty-eight ; on the 7th, twenty-two ; and on the 

 8th, fourteen. Just as occurs in India and elsewhere, a violent epi- 

 demic generally subsides rapidly. 



The further one investigates the drinking-water theory the more 

 and more improbable does it appear. Robert Koch, too, the famous 

 bacteriologist, has hitherto failed to substantiate the drinking-water 

 theory, and I feel convinced that the time is not far distant when he 

 will own that he has gone in the wrong direction. Koch has suc- 

 ceeded in finding the comma bacillus in a water-tank in a region where 

 cholera was prevalent. I have the greatest respect for this important 

 discovery, not as a solution of the cholera question, but only as a very 

 promising field for pathological, not epidemiological, inquiry. It must 

 be remembered that cholera was already prevalent in the neighborhood 

 of the water-tank from which Koch obtained the bacillus. Now, this 

 tank was used not only for drinking purposes, but also for bathing the 

 person and washing clothes, as Koch himself admits. According to 

 my view the comma bacillus must have been present in the water. It 



