14 BULLETIN 989, U. S. DEPARTMENT OF AGRICULTURE. 
the year from 1.45 to 3.23. The greatest individual drop in one year 
was from 1.71 when freshly made to 1.45 at the end of the year. 
The average was 2.47 when freshly prepared, 2.52 at the end of 
the month, and 2.46 at the end of the year. No detericration could 
be demonstrated. It should be noted that these samples varied one 
trom the other more markedly than did the Hygienic Laboratory 
pine-oil disinfectants, one showing a coefficient of 1.71, another a 
coefficient of 3.42. 
Two samples of the wood naphtha oil emulsion were examined. 
One gave a coefficient of 0.70 when freshly prepared, 0.60 at the 
end of a month, and 0.60 at the end of a year. The other gave a 
coefficient of between 0.54 and 0.60 when fresh, 0.44 at the end of 
a month, and 0.45 at the end of a year. The slight decrease in the 
coefficient noted at the end of the first month is too small to indicate 
any definite deterioration. 
A sample of “ light” crude-oil emulsion gave a coefficient of 0.85 
when fresh, 0.75 at the end of a month, and 0.90 at the end of the 
year. A second sample, examined within a month of its manufac- 
ture, showed a coefficient of 0.84. At the end of the year the coeffi- 
cient was 1.03. | 
A sample of the “heavy” crude-oil emuision had a coefficient of 
0.74 when examined in the first month. “At the end of a year it 
was 0.78. . 
A sample of emulsion made from the entire crude oil gave a coeffi- 
cient of 0.60 when fresh, 0.64 at the end of the month, and 0.64 at 
the end of the year. A second sample gave a coefficient of 0.74 at 
the end of a month, and 0.85 at the end of the year. 
Two samples of tar-oil emulsions showed coefficients of 0.82 and 
0.70 in the first month, and 0.84 and 0.83, respectively, at the end of 
a year. 
The-action of these samples on J/. aureus and B. anthracis was 
similar to that of the Hygienic Laboratory pine-oil disinfectant. 
That is to say, when tested against J/. aureus strain 200, they gave 
Rideal-Walker coefficients ranging from none to 0.7, but when tested 
against strains 202 and 203, they failed to kill in any dilution. Like- 
wise they failed to all B. anthracis in 5 and 10 per cent emulsions. 
CONCLUSIONS. 
Pine-oil emulsions made from steam-distilled pine oils, when 
freshly prepared, gave Hygienic Laboratory coefficients varying from 
3.42 to 4.34, the average being 3.88. At the end of 12 months the 
average was 3.66. 
A disinfectant prepared from destructive-distilled pine oil is - 
weaker as well as more variable in its germicidal power against B. 
typhosus than is the Hygienic Laboratory pine-oil disinfectant. The 
