84 
EXPERIMENT NO. 46. 
Formalin, 2,000 c. c.; permanganate, 1,000 grams, equally distributed in four galvanized-iron 
buckets, two of which, were placed in the main sleeping compartment and one in the alley- 
way at each end. 
Weather: Clear, practically no wind. 
Temperature in car at beginning of experiment, 73° F. 
Relative humidity in car at beginning of experiment, 61 per cent. 
Time of exposure, 2 hours (11.45 a. m. to 1.45 p. m.). 
Temperature in car after opening and airing 15 minutes, 83° F. 
Relative humidity in car after opening and airing 15 minutes, 45 per cent. 
[+ means growth; — no growth.] 
Organism. 
Place of exposure in car. 
Result. 
B. coli communis 
Toilet room 
Drawing-room 
Floor, main sleeping compartment ; . ; j'R . . _ 
Berth, upper No. 8 
Berth, lower No. 9 1!'... 
B . diphtherias 
Toilet room 
D ra wing-room 
Floor, main sleeping compartment 
Berth, lower No. 12 
B. typhosus 
Berth, upper No. 8 
Toilet room 
Drawing-room 
Floor, main sleeping compartment 
Berth, lower No. 6 
— 
Berth, upper No. 10 
B. subtiiis 
Toilet room 
+ 
D ra wing-room 
+ 
Floor, main sleeping compartment 
+ 
Berth, upper No. 4 
+ 
Berth, lower No. 4 
+ 
B. tuberculosis 
Floor, main sleeping compartment 
+ 
Sputum exposed by Wilson method and injected into guinea 
pig; pig chloroformed 25th day; increased 250 grams in weight; 
lesions of tuberculosis in spleen and lymph glands. 
Floor, main sleeping compartment 
+ 
Sputum exposed on carpet and injected into guinea pig; pig 
chloroformed 95th day; lesions of tuberculosis in spleen and lungs. 
Control guinea pig died of tuberculosis 60th day. 
Under ordinary conditions in disinfecting sleeping cars the formalin- 
permanganate method practically accomplishes complete surface dis- 
infection when the weather is warm and the relative humidity high. 
The exact temperature and percentage of relative humidity necessary 
can not be stated within a few degrees, but it will be seen from the 
experiments that when the temperature is above 74° F. and the rela- 
tive humidity above 61 per cent nearly all the nonspore-bearing organ- 
isms exposed to the action of the gas were killed within 2 hours. 
Frequently old subtiiis spores were killed in the short exposure of 
2 hours, as will be seen in the experiments. Most of the tubercle 
bacilli exposed to the action of the gas were also killed in this time. 
In a few instances tubercle bacilli were not killed, but they were dimin- 
ished in virulence. It is probable that a longer exposure than 2 hours 
would be more effective in this regard. 
