dead, with as little delay as possible, should be buried in deep graves or cremated. Isolated observation camps should be organized, in which " suspects " and " contacts " may be segregated for a time equal at least to the incubation period of the disease. Rats and mice should be poisoned or otherwise destroyed, and their bodies burned. Besides such special measures, general sanitation should be scrupulously carried out. The diffusion of plague by railways must be carefully guarded against.
In the event of an outbreak in a town, it must be borne in mind— first, that there is an intimate connection between rat plague and human plague; second, that rat plague is conveyed to human beings, and, once established in human beings, is communicable to others and to rats by means of the expectoration, by the discharges from the bowels and by the urine, and by discharges from the buboes or glandular swellings; and third, that a plague in rats usually precedes plague in human beings. It is as important to know in what houses, areas, and quarters of the town the rats are infected as it is to know in which of these there are plague patients. In addition, therefore, to prompt notification of plague patients, a system designed to obtain information as to the occurrence of plague in rats should be instituted. It is not sufficient to carry on a general campaign against rats, and to burn all rats which have been poisoned or caught in traps, but it is necessary also daily to examine bacteriologically every rat so destroyed, in order to determine whether it is healthy or infected, and so to differentiate the healthy from the infected parts of the town. A ticket on the rat, giving the address from which it was brought, locates the street and house, and permits of action being taken at once. A house in which a plague rat is found is a plague- infected house, and if plague among the inmates is to be prevented the necessary preventive measures should be taken at once. These measures consist in the evacuation of the house until it has been
