10 
2^utrient bouillon containing various percentages of glycerin (-S'.), contaminated by the 
addition of stable manure, and J:ept inflashs at room temperature. 
Percentage of glycerin. 
Day npon -wMcli growth, appeared. 
hinth day. 
Tenth day. 
Thirteenth day. 
Twenty-first 
day. 
41 per cent 
Small snrface 
mold. 
Xo growth. 
Do. 
42 per cent 
>m all >nrfapp _ 
43 per cent 
mold. 
Very .gmall snr- 
■ face mold. 
44 per cent 
45 per cent 
46 per cent 
Small snrface 
mold. 
As was to be expected, the exact percentage of glycerin necessary to 
restrain growth varies within narrow limits with the make of glvcerin 
used and the kind of contamination. 
To sum up the antiseptic power of glycerin: 
Per cent. 
Glycerin X 49 
Glycerin M 45 
Glycerin P 43 
Glyc-erin S 45 
Average - 45. 5 
These results do not correspond with ^liquehs work in 18S1. who 
found that 225 grams of glvcerin in 1 liter of bouillon was sufficient 
to prevent putrefaction. 
The above test having deteiTuined the antiseptic power of glycerin 
against putrefactive changes, another series of exi^eilments was made 
in order to determine the restraining power of glycerin against pure 
cultures of various micro-organisms. 
The different percentages of glycerin were made as before with 
nutrient bouillon and this time distributed into test tubes. Each tube 
was inoculated with a minute but visible portion of the surface growth 
of the organisms, which were grown for this pui’pose upon agar slants 
under favorable conditions, and fresh young cultures were always used 
to make the inoculation. 
The test tubes were incubated at 37' C. and examined daily for 
growth. In case a growth appeared it was tested for purity. The 
tubes were observed dailv for at least eleven davs and the result noted. 
