EXPERIMENTAL MXKLING AND BAKTXCi. 
35 
Determination. — Place 100 grams of wheat, together with 150 cubic 
centimeters of oil, in the distillation flask and shake with a slight 
whirling motion until the two become well mixed. Insert the ther- 
mometer so that the mercury bulb will be immersed approximately 
three-fourths of its length. Place the flask in the heating compart- 
ment, connect with the condenser tubes, have a stream of water 
running through condenser tank, place graduated tubes under the 
condenser tubes, and start flame. Extinguish the flame when the 
thermometer reaches 180° C. for wheat, and let the mercury recede 
to 160° C. before making reading. It is absolutely necessary to 
adhere to these directions to secure correct results. 
In this connection it should be stated that up to this time the 
gas-heated Brown-Duvel machine is the only type that has given 
Fig. 27.— Bench showing Boerner sampler, test weight per bushel apparatus, and balance for weighing 
satisfactory service for moisture tests. The electrically heated ma- 
chines have not been perfected to the point where the heat units 
(wattage) can be conveniently controlled to give accurate results. 
The Brown-Duvel moisture tester with gas-pressure regulator in place 
is shown in Figure 29. 
ASH IN FLOUR AND MEAL. 
To make an ash determination of flour or meal, weigh duplicate 
3-gram portions of the material into a previously ignited and weighed 
porcelain combustion capsule. Place in an electric muffle and heat 
gradually until the color of the inside of the oven is a dull red. 
Maintain at this temperature overnight. The ash is not fused by 
this method and is white to gray-white in color. In the morning 
remove to a desiccator and allow to cool. Reweigh the capsule and 
consider the gain in weight as ash. 
