UNITED STATES DEPARTMENT OF AGRICULTURE 
I BULLETIN No. 855 
Contribution from the Bureau of Animal Industry 
jgy^y^ JOHN R. MOHLER, Chief 
Washington, D. C. PROFESSIONAL PAPER May 6, 1920 
SAPONIFIED CRESOL SOLUTIONS 
By Jacob M. Schaffer, Junior Chemist, Biochemic Division 
CONTENTS 
Properties of mixtures with rosin soap 2 
Observations on speed of dilution 3 
Cost of materials used 4 
Summary 5 
This paper describes a series of experiments undertaken with the 
object of preparing a saponified cresol solution which would be 
cheaper and at the same time no less effective as a disinfectant than 
those at present in use. Such a product should contain the usual 50 
per cent cresol with the necessary quantity of soap to insure complete 
solubility in water and should meet the following requirements: 
The product shall remain a homogeneous liquid when cooled to 32° F. It shall 
contain substantially no free oil, fatty acid, or excess alkali. It shall be readily 
soluble in cold distilled water; the solution shall be practically clear and shall contain 
no globules of undissolved oil or cresylic acid. 1 
By stating the qualifications of a good finished product the Bureau 
of Animal Industry has safeguarded itself and at the same time 
allowed the manufacturer to mix the necessary ingredients in the 
manner he finds most economical. 
Disinfectants made with cresylic acid and rosin soap have been 
objected to because they become cloudy when diluted with water. 
In the case of a cresol-rosin soap solution diluted with water to a 
3 per cent solution and exposed in a flask to the air, it has been found 
that the clouding is due to the hydrolysis of the rosin soap and the 
absorption of carbon dioxid from the air, the rosin being precipitated 
at first in finely divided particles. After a few days these particles 
commence to agglomerate and settle to the bottom; finally, after 
about two weeks, equilibrium is reached, the solution clears, and 
shows a good deal of rosin in a mass at the bottom of the 
i U. S. Bureau of Animal Industry Order 263. 
171564°— 20 
