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E. Abel (a) used pure cultures from bouillon, agar-agar and blood 
serum, or pus from the peritoneal cavity of guinea pigs, containing the 
bacillus pestis. These were planted on various objects — glass cover 
slips, silk, wool, woolen cloth, linen, and pieces of ox skin, and in 
sterile earth. Also pieces of the organs, liver, and spleen of animals 
dead of plague were dried. Apx>roximately similar sizes were taken 
every day from each object. The result of these experiments showed 
that the manner of drying influenced the viability of the pest bacillus. 
Xo matter on what material, the result of drying at the temperature of 
35° C. in the incubator, or 20° C. in vacuo over sulphuric acid, the 
bacillus was always found dead in two, or at most, four days. If the 
drying was permitted at the room temperature, 16° to 20° C. in a dark 
place, the bacilli remained alive much longer and the material in which 
they were dried markedly influenced the result. 
On cover slips they remained alive six to nine days, from pus and 
cultures. Only once in four tests were the bacilli found alive a longer 
time — fourteen days — but not longer than this. 
On threads of various sorts, on linen, and in pieces of organs, the 
bacilli were found alive after thirty days ; if longer, it could not be 
determined, because the work was interrupted. In the longer exposures 
the threads planted in bouillon and kept undisturbed showed the out- 
growth of isolated colonies here and there, indicating that many of the 
bacilli had lost their power of multiplication. 
He, therefore, concluded that forced drying at a temperature over 
30° C. or by substances that have a high affinity for water such as con- 
centrated sulphuric acid, the bacillus pestis dies cpiickly. Slower dry- 
ing at lower temperature is less harmful. However, even at room 
temperature the quicker drying, such as on a cover glass, is more harm- 
ful to the bacillus than the slower drying on pieces of cloth or in pieces 
of tissue. 
“ The fact that the bacillus remains alive longer when dried at 16° to 
20° C. than was at flrst announced, teaches that in our climate (Ham- 
burg) at least, we can not expect the organism to quickly disappear in 
clothing, etc.’’ 
On fresh shin the bacillus was found alive after ten days. These tests 
were not altogether satisfactory because the sterilizing of the skin before 
infecting it with pest was not successful after washing and eight days’ 
immersion in ether and alcohol. It is possible that the bacilli are alive 
after ten days, though not demonstrable on account of the growth of 
other organisms. 
Further tests, are being made with cultures, and the bacillus in blood 
and organs placed on various objects, and kept under various conditions, 
report on which will be submitted later. 
Martin Ficker (6) tested the effect of drying and moisture alter- 
a Zur Kenntuis des Pestbacillus. Centralblat fiir Bakteriologie und Parasitenkunde, 
etc., Bd. XXI, 1897, page 497. 
ftZeitscbrift fur Hygiene, Bd. XXXIX, 1898, page 25. 
