Page:Popular Science Monthly Volume 26.djvu/643

Rh from without and the first cases of illness occurring in a place, as happened in 1883 at Damietta in Egypt, and in 1884 at Toulon in France. The germs may have arrived six months before without finding the necessary material for their growth, and consequently may die out before giving any signs of their existence.

How long the germs of cholera may remain latent in a place we have no evidence to show. There are cases in which we might say that a whole year elapses, but instead of that I think it can be shown that in Europe the germs die out. Since cholera has lasted for many years in Russia, some epidemiologists have supposed that in Russia in the North, just as in Lower Bengal in the South, cholera is endemic. The history of cholera, however, in two islands of the Mediterranean, Malta and Gozo, supplies an example to the effect that the germs of cholera may die out in the space of a few years, and that the germs must be again imported before fresh cases of Asiatic cholera can appear. The Islands of Malta and Gozo lie near one another, and are by nature so similar that it might be imagined that a single homogeneous rock had been split into two parts, a greater and a smaller, which lie as near together as possible in the water without touching one another. It is thus that the two islands project from the sea. Each has the same kind of soil, enjoys the same winds, the same sunshine and rain, the same population of Arabic origin, with like manners, customs, and daily intercourse. Vegetables, fruit, and cattle for slaughter pass daily from Gozo to Malta. The two islands differ in that Gozo has no direct intercourse with the world at large, while Malta is famous for its natural harbor. Both islands have experienced epidemics of cholera, but Malta was always invaded some weeks before Gozo. Finally, both islands show themselves equally susceptible to cholera. In 1865 in Malta 12 per 1,000 of the population, and in Gozo 10 per 1,000, died of cholera. The first case of cholera occurred in 1837 on May 26th in Malta, and on July 5th in Gozo; in 1850 it was June 9th and August 28th respectively. In 1854 and 1856, during the Crimean War, cases of cholera appeared in Malta and Gozo, but not in an epidemic form; nevertheless, sporadic cases first showed themselves in Malta. In the epidemic of 1865 the first case occurred in Malta on June 28th, and in Gozo on July 21st. This interval of time between Malta and Gozo makes me suspicious of the current doctrine that cholera can occur in places two days after the arrival of the infecting cases; for it has not been proved that cases might have arrived still earlier. The instance of Malta and Gozo clearly proves that cholera may have no long duration, that it is not autochthonic, that it is not brought by the wind, but that for its passage intercourse is necessary.

The facts of the influence of locality the contagionists can not deny; indeed, they accept the facts, but explain them in another way. Attempts are made to show by the localists and contagionists, how the germs of cholera spread by means of human intercourse may act