CHOLERA.
Cholera, which was formerly so prevalent, now seldom occurs in this country, and at each successive visit to England its inroads have become less serious. At its last visit in 1893 it scarcely obtained a footing in the country. Thus in the epidemic of 1854 in England it caused 1080, in that of 1866 it caused 672, and in that of 1893 only 45 deaths per million of population. In this country at least it is chiefly spread by infected water and foods, especially by infected water; and the preceding figures form an excellent testimony to our improvement in this respect. For particulars of the Hamburg outbreak, see page [93]. In its mode of prevalence and propagation it is very similar to enteric fever, being infectious by means of the evacuations. The means of prevention are the same as for enteric fever. Cholera was shown by Koch to be caused by what is known as the comma bacillus or spirillum of Asiatic cholera, so called because of its curved shape. It is from 1·5µ to 2·6µ long and ·5µ broad. For the supposed connection of enteric fever and cholera with movements of the ground-water, see page [225].