6 
The others were exposed to ammonia before inoculation into bouillon, 
with the following result : 
Typhoid (3 slips), all grew. 
Anthrax (3 slips), all grew. 
Diphtheria (3 slips), all grew. 
It will therefore be seen that the formaldehyd inhibited but did not 
kill the typhoid and diphtheria, for no visible growth was obtained 
from the slips planted directly from their formaldehyd exposures into 
bouillon, whereas, those first treated with ammonia showed a good 
growth. 
It is therefore reasonable to suppose that in some instances through- 
out this work the same phenomenon resulted, especially in the tests in 
which the trace of formaldehyd was not neutralized with ammonia. 
This possible error, however, does not effect the conclusions diawn 
from the work, because the results obtained show that formalin when 
used in a closed container has feeble powers of penetration and can not 
be recommended as a safe and effective disinfectant. 
If some of the cultures exposed were inhibited and not killed this 
conclusion would be still more positive. 
The bouillon tubes inoculated with the slips of paper are incubated 
at 37° 0. In case a growth does not appear, they are kept at least ten 
days, frequently two or three weeks, before discarding. 
In many instances the growth was found to be retarded. Xo visible 
growth before five to seven days. 
In case the tubes showed positively the growth was always tested for 
purity. In few instances contamination crept in^ usually a mold from 
the air or a rod resembling subtillis. 
Control slips were always kept under equal conditions for twenty-four 
hours and inoculated as above to verify every test. 
ViaMlity of cultures. 
The cultures used in these observations were anthrax, diphtheria, and 
typhoid. When exj)osed in bouillon cultures to heat they gave the 
following results : 
Typhoid — 
Five minutes at 65° 0., growth. 
Ten minutes at 65° C., growth. 
' Fifteen minutes at 65° C., slight growth. 
Twenty minutes at 65° 0,, no growth. 
Diphtheria — 
Five minutes at 65° C., growth. 
Ten minutes at 65° C., growth. 
Fifteen minutes at 65° C., no growth. 
Twenty minutes at 65° C., no growth. 
