remained exempt. In December, 1848, cholera was brought from Europe, by emigrant ships, both to New York and to New Orleans. From the lastnamed city it spread northward to Memphis and westward into the State of Texas, and during the year 1849 nearly all of the States east of the Rocky Mountains suffered to a greater or less extent, especially those located in the valleys of the Ohio and Mississippi rivers. It continued to prevail during the following year (1850), and in October was carried to San Francisco by way of the Isthmus of Panama. During this epidemic the West Indies suffered severely, especially the islands of Cuba and Jamaica. It also prevailed in Mexico, and to some extent in South America. The epidemic did not terminate in the Western Hemisphere until the end of the year 1854, but in Europe it had practically ceased to prevail, except in a few localities in northern Europe, by the close of the year 1850.

In the spring of 1852 another widespread epidemic was inaugurated. The disease appeared almost at the same time in Persia, Mesopotamia, and Poland, apparently as a survival from the previous epidemic, and extended to adjacent countries. In Russia it continued to prevail to some extent during a period of ten years, the years 1853, 1855, and 1859 being notable as marking its widest extension and the

greatest mortality. This was also the case in northern Germany. In 1855, Austria and Italy suffered severely. The disease was brought to England from Germany in 1853 and extended to various parts of the island during this and the following year. France also suffered severely from the disease at this time (1853-54), and also Spain and Portugal, where it prevailed during the period from 1853 to 1860. In North America the disease was introduced into Canada in 1853, and obtained wide extension throughout the United States in 1854. The disease disappeared from the countries of North America the following year, but in Central America and in South America it prevailed to some extent for several years subsequent to this date, although the year 1855 was that of greatest extension and fatality.

Another epidemic period is that embraced between the years 1865 and 1875. As usual, the epidemic extension of the disease in Europe was preceded by a period of increased fatality in its native haunts, in the lower basin of the Ganges, and also by its extension to other eastern countries - China, Japan. I shall not attempt to follow the progress of the disease through the countries of Europe, but, as showing its fatal character, will give some mortality statistics. The epidemic of 1867 in Italy was attended by a mortality of 130,000. In Prussia, during

the year '1866, 114,683 deaths were reported. In England the disease, in 1865 and the next year, caused a mortality of 14,378, nearly half of the deaths occurring in the city of London. In Belgium a mortality of 32,812 occurred during the year of greatest prevalence (1866).

In North America the disease was introduced in 1866 by three independent importations, to New York, New Orleans, and Halifax. The following year it obtained wide extension, especially in the western States and in Texas.

Again cholera invaded Europe during 1871-73, and again it was introduced into the United States by way of New Orleans, and thence spread to some extent in the valley of the Mississippi, and along its principal tributaries. The epidemic of 1872 is estimated to have cost 120,000 lives in Russia, and the previous year the mortality was still greater. In Hungary the disease claimed 190,000 victims during the years 1872 and 1873. In Prussia the number of deaths in 1873 was 28,790.

Cholera disappeared from Europe and America in 1873, and the next great epidemic was inaugurated in 1884, when it reached the shores of France and Italy. According to Dr. Shakespeare,' this epidemic "cost France 15,000 of its inhabitants in 1884, 1885,

1Report on Cholera in Europe and India, by E. O. Shakespeare, M.D. (1890).

and 1886; Spain, 180,000 in 1884 and 1885; Austria-Hungary, 4000 inhabitants in 1886; Italy, about 50,000 inhabitants in 1884, 1886, and 1887."

In Japan, the epidemic of 1885 was attended with a mortality of 109,434.

In 1891 cholera prevailed extensively in India, Syria, Arabia, Siam, and Japan, and was introduced into Austria by way of Persia. By November, 1892, it is estimated that half a million cases had occurred in Russia with a mortality of at least 50 per cent. A severe outbreak of the disease occurred in the city of Hamburg during the month of August of this year, resulting in 8005 deaths. From Hamburg the disease was brought to New York harbour on several ships carrying immigrants, but owing to the vigorous measures adopted by the local health authorities, assisted by the Marine Hospital Service, the disease was arrested at the threshold of the country and an epidemic was averted. The success obtained at this time shows what can be accomplished by sanitary measures based upon an exact knowledge with reference to the specific cause of the disease (cholera germ) and its mode of transmission. The extension of cholera from its home in India to the countries of Europe and America, which first occurred during the nineteenth century, was no doubt due to the increased facilities for rapid transit, especially by steamboats

and railroads. Infected individuals leaving the localities where they had contracted the disease, would fall by the way, or recover before travelling any great distance, if restricted to the methods of transportation available before the introduction of steam as a motive power for ships and railroad coaches. The fact that cholera is carried from place to place by men, following routes of travel, is well stated by the German physician Griesinger. He says:

Cholera has never advanced like a broad stream inundating entire countries at one time, bringing disease to all regions lying parallel with each other, over a wide extent, but it always advances in relatively narrow lines from which usually, but not always, lateral offshoots arise. In countries with a small population we see constantly that this district corresponds with the great lines of travel. If the disease oversteps high mountains, if it passes through a desert, if it crosses the ocean, it always follows the lines of human intercourse, the post and military routes, the caravan and sailing routes, etc. If it has broken out on an island, then the first cases have always been in a seaport, never in the interior."

We now know definitely that the cholera germ is carried from place to place by cholera-infected individuals, who harbour this deadly spirillum in their intestines and leave it wherever the discharges from their bowels are deposited. Mild cases of "choleraic diarrhoea" are even more dangerous as regards the propagation of the disease than severe and fatal cases, for the infected individual may not suspect the nature