BUTTER 85 
mination of the volatile acid, but some other 
confirmatory processes are occasionally employed. 
QUALITATIVE TESTS.—Two tests are convenient 
for preliminary examinations, especially for sort- 
ing out, when many samples are to be tested. 
The experience of Dr. William Beam and myself 
in testing many hundred samples for the Dairy 
and Food Commissioner of Pennsylvania showed 
that the methods are satisfactory and useful. 
Heating test—When butter is heated in a 
small tin dish directly over a gas flame, it melts 
quietly, foams, and may run over the dish. 
Oleomargarin, under the same conditions, sput- 
ters noisily as soon as heated and foams but little. 
Even mixtures of butter and other fats show this 
sputtering action to a considerable extent. The 
test is not applicable to butter which has been 
melted and reworked (renovated or process 
‘butter). 
Saponification test—An alcoholic solution of 
sodium hydroxid, boiled up with butter, and then 
emptied into cold water, gives a distinct odor of 
pineapples, while oleomargarin gives only the 
alcoholic odor. 
QUANTITATIVE MeEtHOps. Volatile Acids.— 
This method, suggested by Hehner & Angell, 
systematized by Reichert, is generally called the 
Reichert process. In this form it is carried 
out by saponifying 2.5 grams of the fat, adding 
