The quantity of potassic hydrate required to saponify one gramme or 15
grains of pure beeswax varies from 97 to 107 milligrammes. Other kinds
of wax and its substitutes require in some cases more and in others
less of the alkali. This method would, however, lead to very erroneous
conclusions if applied to a mixture of which some of the constituents
have higher saponification numbers than beeswax and others higher, as
one error would balance the other.

To avoid this, the quantity of alkali required to saponify the
myricine is first ascertained, and then that required to saturate the
free cerotic acid. In this way two numbers are obtained; and in an
investigation of twenty samples of Austrian yellow beeswax, the author
found these numbers stood to each other almost in the constant ratio
of 1 to 3.70. Although this ratio cannot be considered as definitely
established by so few experiments, it may serve as a guide in judging
of the purity of beeswax.

The experiment is carried out as follows: 3 or 4 grammes of the wax
that has been melted in water are put in 20 c.c. of neutral 95 per
cent, alcohol, and warmed until the wax melts, when phenolphthaleine
is added, and enough of an alcoholic solution of potash run in from a
burette until on shaking it retains a faint but permanent red color.
The burette used by the author is divided in 0.05 c.c. After adding 20
c.c. more of a half normal potash solution, it is heated on a water
bath for ¾ hour. Then the uncombined excess of alkali is titrated with
half normal hydrochloric acid. The alcohol must be tested as to its
reaction before using it, and carefully neutralized with the acid of
phenolphthalein.

To saturate the free acid in 1 gramme of wax requires 19 to 21