ACTION OF SALTS. 191 
the presence of 1 : 300,000 in a culture medium, and Geppert has re- 
cently shown that even so small an amount as 1 : 2,000,000 will pre- 
vent the development of spores the vitality of which has been reduced 
by the action of a strong solution (1:1,000). When this restraining 
action is entirely neutralized by washing the spores in a solution con- 
taining ammonium sulphide it requires, according to Geppert, a solu- 
tion of 1:1,000 acting for one hour to completely destroy the vitality 
of anthrax spores. Frankel found that a solution of 1:1,000 was 
effective in half an hour. The typhoid bacillus, the bacillus of mouse 
septicemia, and the cholera spirillum, in bouillon cultures and in 
cultures in flesh-peptone-gelatin, are destroyed in two hours by 
1:10,000; but in a bouillon culture to which ten per cent of dried 
egg albumin was added a one-per-cent solution was required to de- 
stroy the typhoid bacillus in the same time (Bolton). According to 
Van Ermengem, cultures of the cholera spirillum in bouillon are steril- 
ized in half an hour by 1 : 60,000, but culturesin blood serum require 
1:800 to 1:1,000. In experiments upon tuberculous sputum Schill 
and Fischer found that exposure of fresh sputum to an equal amount 
of a 1: 2,000 solution for twenty-four hours failed to disinfect it, as 
shown by inoculation experiments in guinea-pigs. The antiseptic 
power of mercuric chloride is given by Miquel as 1:14,300. In the 
writer’s experiments 1 : 33,000 was found to prevent the development 
of putrefactive bacteria in bouillon, but a minute bacillus contained in 
broken-down beef infusion multiplied, after several days, in 1 : 20,000. 
The pus cocci were restrained in their development by 1 : 30,000. 
In Behring’s experiments the anthrax bacillus and cholera spiril- 
lum were killed in one hour by 1:100,000 when the temperature 
was 36° C., but at a temperature of 3° C. the proportion required 
"was 1:25,000. The same author states that at 22° C. Staphylo- 
coccus aureus in bouillon is not always killed in twenty-five minutes 
by 1:1,000. 
Abbott (1891) has shown that a 1:1,000 solution does not always 
destroy Staphylococcus pyogenes aureus in five minutes. He says: 
“ Frequently all the organisms would be destroyed after five minutes’ 
exposure, but almost as often a certain few would resist for that 
length of time, and even longer, going in some cases to ten, twenty, 
and even thirty minutes.” 
According to Yersin, a solution of 1 : 1,000 kills the tubercle bacil- 
lus in one minute. 
We might add considerably to the experimental data given, but 
the results already recorded are sufficient to show the value of this 
agent as an antiseptic and germicide, and justify its use for general 
purposes of disinfection in the proportion of 1:500 or 1:1,000 for 
material containing spores, and in the proportion of 1:2,000 to 
