2 BULLETIN 1308, U. S. DEPARTMENT OF AGRICULTURE 
fications, such as a requirement for a minimum content of total 
phenols by analysis and a restriction on excess alkali, were aimed 
either to insure uniform effectiveness or to reduce the chance of 
injury to animals. 
The standard procedure for the chemical examination of saponi- 
fied cresol solutions has been one developed by the writer (1). Its 
chief merit has lain in the circumstance that different analysts could 
obtain results in good agreement, so that wherever it has been con- 
sistently employed by manufacturers, consumers, and regulatory 
officials there has been little room for dispute over the analytical 
data pertaining to a given sample. But because it is cumbersome 
and -tedious it is not well adapted to afford the ready control desirable 
for such products, particularly in the plant laboratory. The purpose 
of the present paper is to present a procedure which is rapid and 
simple enough for the plant laboratory and sufficiently precise and 
accurate for use by the regulatory official. At present this procedure 
is limited to saponified cresol solutions, composed essentially of 
cresol and soap, and has not been extended to coal-tar-creosote dips 
and disinfectants. 
FUNDAMENTAL REQUIREMENTS FOR SAPONIFIED CRESOL 
SOLUTIONS 
In order to devise an appropriate procedure for testing a com- 
mercial preparation designed for a specific use, it is first necessary 
to understand the exact functions which the preparation is called upon 
to perform and the range of external conditions under which it must 
successfully perform them. In the work of the Bureau of Animal 
Industry the functions of a saponified cresol solution are (1) to 
make inactive the germs of certain diseases, (2) to devitalize certain 
insects which cause disease either directly or by acting as inter- 
mediate hosts for disease-producing organisms, and (3) to destroy 
the vitality- of the eggs of such insects. To accomplish these results 
it is sometimes necessary to disinfect the whole surface of the ani- 
mals themselves by dipping or spraying, in which case the prepara- 
tion must not cause injury to the animals. Under practical condi- 
tions of use it is frequently impossible to protect the concentrated 
preparation against long exposure to a low temperature during trans- 
portation and storage. Again, before it can be used it must be dis- 
solved in water, and frequently this means that the solution must 
be prepared in rather large quantities with cold water, which may 
also be hard water, by men not especially versed in such manipula- 
tions, working with scanty equipment in physical discomfort and 
pressed for time. 
Given the exact functions and the conditions under which the 
preparation must perform these functions, the next step is to formu- 
late an appropriate set of specifications. In the present discussion 
it is proper to suggest only the general form which such specifica- 
tions may take, leaving precise details and limits to be promulgated 
by the bureau in the form of regulatory orders. 
UNIFORMITY AT LOW TEMPERATURES 
A saponified cresol solution normally becomes more viscous when 
chilled and may even set to a jelly which can not be poured from the 
container. Material in such a condition might be highly inconvenient 
