16 
Hankin worked with linseed, yellow rape seed, brown rape seed, til- 
seed or ginjelly seed, ground nuts, castor seeds, poppy seeds, wheat 
(new hard red), wheat (another light variety), flour. 
In order to test whether the microbe was still present in a living con- 
dition in a specimen of previously infected grain his method consisted 
of making an extract of this grain and injecting it into a mouse. 
He used agar cultures making bouillon suspensions. About a kilo- 
gram of grain to be tested was placed in a sterile stoppered foot glass. 
One c. c. of the bouillon emulsion of the microbe was then poured into 
the foot glass, care being taken that it should fall into the center of the 
grain. The stopper was replaced and the foot glass was immediately 
violently shaken for about one quarter of an hour. 
Extracts made from the grain in this manner were inoculated into 
mice with the following results : 
Extract of the fol- 
lowing injected 
into mice. 
At once after 
infecting the 
grain. 
Two days after 
infecting the 
grain. 
Four days 
after infecting 
the grain. 
Eleven days 
after infecting 
the grain. 
Linseed 
Yellow rape seed 
Brown rape seed 
Tilsppfl 
Died within 
24 hours. 
Died within 
72 hours. 
Died within 
48 hours. 
Died within 
24 hours. 
do 
Died after 7 
days. 
Died after 24 
hours. 
Died after 4 
days. 
Survived 
Died after 15 
days. 
Survived 
do 
Survived 
do 
Died after 24 
hours. 
Died after 7 
days. 
Died after 24 
hours. 
do 
rj-rminH niits 
Died after 11 
days. 
Died after 48 
hours. 
Survived 
do 
Pnppy sppd 
do 
do 
Wheat (new hard 
red). 
Wheat (another 
kind). 
Plniir 
Died within 
48 hours. 
Survived 
do 
do 
do 
do 
Died within 
48 hours. 
Died after 48 
hours. 
Thirteen days 
after infecting 
the grain. 
Survived. 
Died after 24 
hours. 
Survived. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Hankin concludes from these experiments that the bubonic microbe 
derived from pure cultures perishes within thirteen days after being 
added to the above-mentioned specimens of grain and seeds. 
Further experiments were made with grain and seeds by mixing the 
spleen of a rat and the liver, spleen, and oedema from a mouse, both 
animals having died after plague infection, instead of cultures of the 
organism. The organs were powdered up in a mortar with powdered 
glass and mixed with bouillon and added to the grain and seed. The 
further proceedings were as above. 
The result of this showed that grain infected with the organs of 
animals dead of the plague lost its infectious power completely within 
six days. 
Another set of experiments was then conducted by infecting the grain 
with sputum from a case of pneumonic plague. Sputum was taken, in 
which the organism was demonstrated to exist in large numbers in very 
virulent condition. 
These also showed the plague infection to die out from all the variety 
of seed and grain tested within six days. 
