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reported by Rocher and Baber to be sometimes infected. (4) The very large boating population of Canton, the Tan-kid said to number some 50,000 odd, have been quite free from the disease, while whole families have died in houses alongside creeks in which these house boats are lying.
Many of the above facts go to shew that the plague is not easily caught, if at all, by infection from the air or contagion from the persons of the sick. It would seem that the contagion must be carried to a nidus as described above where temperature, moisture and such conditions being favourable the active poi- son will be bred.
The Chinese pamphlet by Mr Wu has the fol- lowing remarks with regard to the disease at Kao Chou in April 1891 "those who have had the disease in their families say that it is due to the earth and not to the air; for houses with black damp earthen floors had the disease while those with brick or concrete floors escaped, those living in dark unventilated houses died, while those living in upper storeys es- caped, and again of those in the same house, maids and boys who sleep and are often playing about on the ground died in the greatest numbers, women next, who are much in the house and next young men staying quietly at home; when the plague is prevalent the houses are hotter than usual so that the air is drawn from the ground. Fresh air is very important as the following example shews:- Persons have been carried out of doors apparent- ly dead, and yet on their clothes being stolen and their
bodies