1901 - 2 .] Plague Research Laboratory of Government of India. 135 
village during the month previous to inoculation, this would not 
in any way vitiate the results, for, as already described, it was the 
population actually present on the 12th of February that was 
divided into two sections, equal in number as far as possible. As 
regards the second objection, that the number of uninoculated was 
got by subtracting the number inoculated from the figure repre- 
senting the total population, I cannot, at this distance of time, give 
a decided opinion, but I am certain of this, that after the in- 
oculations were done, we checked the numbers inoculated and 
uninoculated, by counting those marked as operated on, in the 
census lists. Now, as I have already shown, these lists had been 
used to get at all the people, and no mistakes had been detected 
in them as we went round, which would inevitably have been the 
case had such existed. As the people were correct according 
to the lists — and granting our arithmetic also correct — it would 
seem an accurate enough mode of arriving at the number of the 
uninoculated to subtract the total of the inoculated from the 
ascertained population, even had we omitted to count the actual 
names, which I do not admit. In conclusion, it may be pointed 
out that these criticisms cannot apply to the population of the 
twenty-eight plague-infected houses, for the inhabitants of these 
were all seen by us both on the days of inoculation and of investi- 
gation. I consider, therefore, that the figures are accurate to a 
high degree, and deductions founded on them worthy of serious 
thought. 
The second example which I propose to give you is of more 
recent date, the outbreak having taken place in February 1900, in 
a ‘chawl’ (or barrack-like house) in the Colaba Ward of Bombay 
city. The chawl was a single-storey building containing ten rooms, 
only eight of which concern us here, arranged in two rows back-to- 
back, separated from one another by 7-foot partitions, but having 
the roof space common to all. All these rooms communicated 
with one another by doors, with the exception of two at one end, 
which were self-contained, but did not, however, escape infection 
on that account. Three rooms did not furnish any cases, though 
some uninoculated persons were living in them. The inhabitants 
all belonged to a low caste of Hindus called Mangs, and would 
therefore mix freely with one another. The chawl was situated 
