ACTION OF ACIDS AND ALKALIES, 185 
killed by three successive applications. In the writer’s experiments 
(1885) the typhoid bacillus and Staphylococcus pyogenes aureus were 
killed in two hours by a solution containing 1:40 of calcium oxide, 
and 1:80 failed. Spores of the anthrax bacillus and of several other 
spore-forming species were not killed by two hours’ exposure toa 
milk of lime containing twenty per cent of calcium oxide. 
Potash Soap has been shown by Jolles (1895) to have considerable 
germicidal value. In experiments with a soap containing 67.44 
per cent of fat acids, 10.4 per cent of combined alkali, and 0.041 
per cent of free alkali, the following results were obtained: The 
typhoid bacillus was destroyed at 18° C. by a one-per-cent solution 
in twenty-four hours; by a six-per-cent solution in thirty minutes. 
The Bacillus coli communis required somewhat stronger solutions or 
longer exposure—eight-per-cent solution required thirty minutes. 
These experiments show that scrubbing with soap and water is a 
reliable method of disinfecting surfaces. Solutions of potash—com- 
mon lye—or of soda also are useful for certain purposes in domes- 
tic disinfection, and scientific researches justify the continued use of 
the cleansing methods which have heretofore been in use by careful 
housewives. 
