operations are verified by Mr. Muentz as follows: He distills in the same
apparatus three to four gallons of chemically pure distilled water, and
ascertains positively that under these conditions iodine and carbonate
of soda give absolutely no reaction. Finally, to complete the
demonstration and to ascertain the approximate quantity of alcohol
contained in natural waters, he undertakes the double fractional
distillation of a certain quantity of pure water to which he has
previously added a one-millionth part of alcohol. Under these
circumstances the iodine and carbonate of soda give a precipitate of
iodoform exactly similar to that obtained by treating natural waters.

[Illustration: Fig. 3.--IODOFORM CRYSTALS OBTAINED DIRECTLY (greatly
magnified).]

[Illustration: FIG. 4,--IODOFORM CRYSTALS OBTAINED WITH RAIN WATER.]

In the case of arable soil, Mr. Muentz stirs up a weighed quantity of the
material to be analyzed in a certain proportion of water, distills it in
the smaller of the two apparatus, and detects the alcohol by means of
the same operation as before.

[Illustration: FIG. 5.--IODOFORM CRYSTALS OBTAINED WITH SNOW WATER.]

The formation of iodoform by precipitation under the action of iodine
and carbonate of soda is a very sensitive test for alcohol. Iodoform
has sharply defined characters which allow of its being very easily
distinguished. Its crystalline form, especially, is entirely typical,
its color is pale yellowish, and, when it is examined under the
microscope, it is seen to be in the form of six-pointed stars precisely
like the crystalline form of snow. Mr. Muentz has not been contented to