?CHAP. II.]	its causes and characteristics.	27
These laboratory
experiments not
conclusive as
demonstrating
the loss of
vitality in the
bacillus.
But the Government of India were advised that these laboratory
experiments, though they may demonstrate the loss of pathogenic
property, are inconclusive as demonstrating the loss of vitality in
the bacillus, which might quite conceivably, although non-pathogenic
at the time of the final experiments, again become pathogenic under
favourable local conditions.
Experience
pointing to
conservation of
vitality.
Example from
Wetljanka.
Dr. Bitter remarks that it seems probable that in a moist condition
the bacillus may retain its vitality for a considerable time in surround-
ings favourable to its life, such as contaminated clothing or bedding,
and experience favours this view. Hirsch recites an example from the
epidemic at Wetljanka in 1878-79. There was a girl of ten years of
age in the house of whose parents a box of clothing had been deposited,
coming from a house in which all the inhabitants had died two
months previously. The girl opened the box, which up to that time
had remained untouched and was about to be burnt. She took a
piece of clothing out and set to work on it, and four days later, the
epidemic having disappeared, the first symptoms of the disease showed
themselves in her.
Instance on a
liner during the
Bombay
epidemic.
Another interesting instance occurred on board a liner during the 
Bombay epidemic. The vessel embarked her crew at Bombay on 
the 20th August and anchored in the Thames on the 11th September. 
There were from three to four hundred passengers on board, and during
the voyage there was no suspicion of plague among them or among the
crew. On the 26th or 27th September one of the Indian Portuguese
stewards fell ill and died on the 3rd October. Clinical and bac-
teriological evidence pointed to plague. Another of the stewards who
slept in the same cabin as the first was also taken ill about the 26th
September and died on the 27th before he could be removed to
hospital. The result of a careful enquiry was to the effect that the
infection was derived from clothing contained in bundles which
remained unopened until the end of the voyage.
Action of
chemical
disinfectants.
Both the German Plague Commission and Mr. Hankin made experi-
ments to test the action of chemical disinfectants on the plague
bacillus. The following is a summary of the conclusions of the German
Commission:-
Experiments of
the German
Commission.
"A solution of corrosive sublimate of the strength of 1:1,000 killed
the bacilli at once. Carbolic acid or lysol of the strength of 1 in 100
killed the bacilli within 10 minutes. When suspensions of the bacilli
were treated with soft soap (3 in 100) or chloride of lime (1 in 100),
they were found after 5 minutes still to contain virulent bacilli, but in
15 minutes sterility had been produced by the chloride of lime, and in
30 minutes by the soap. Sterilised fæces copiously infected with
plague bacilli, and then mixed with equal parts of ordinary milk of