BUTTER 89 
preparing the flask are also from the same 
source. 
When it is intended merely to distinguish 
butter from oleomargarin, it will be sufficient to 
saponify 3 c.c. of the clarified fat, dilute, acidify, 
distil 100 c.c. in the ordinary manner and titrate 
as directed. ‘‘Straight oleos,’’ that is, samples 
containing inappreciable amounts of butter, will 
give a distillate requiring only a few c.c. of alkali. 
Butter (5 grams) yields a distillate requiring 
from 24 to 34.c.c. of N/,, alkali. Several instances 
have been published in which genuine butter has 
given a figure as low as 22.5 c.c., but such results 
are uncommon. The materials employed in 
the preparation of oleomargarin yield a distillate 
requiring less than 1 c.c. of alkali. Commercial 
oleomargarin is usually churned with milk in 
order to secure a butter flavor, and, thus acquiring 
a small amount of butter-fat, yields distillates 
capable of neutralizing from 1 to 2 c.c. of alkali. 
If coconut oil has been used in the preparation 
of the oleomargarin, the figure will be higher, but 
there will still be no difficulty in distinguishing 
pure butter. 
The determination of the Reichert number will 
usually give sufficient information as to the 
nature of a butter sample. In doubtful cases it 
may be of advantage to apply other tests as 
corroborative evidence. 
