are certain to give great
satisfaction, if only a moderate degree of attention and care be
bestowed upon them.--_H. Ewbank, in The Gardeners' Magazine._

* * * * *

RAPHIDES, THE CAUSE OF THE ACRIDITY OF CERTAIN PLANTS.

By R.A. WEBER, Ph.D.

At the last meeting of the American Association for the Advancement of
Science, Prof. W.R. Lazenby reported his studies on the occurrence of
crystals in plants. In this report he expressed the opinion that the
acridity of the Indian turnip was due to the presence of these
crystals or raphides. This opinion was opposed by Prof. Burrill and
other eminent botanists, who claimed that other plants, as the
fuchsia, are not at all acrid, although they contain raphides as
plentifully as the Indian turnip. Here the matter was allowed to rest.

The United States Dispensatory and other works on pharmacy ascribe the
acridity of the Indian turnip to an acrid, extremely volatile
principle insoluble in water, and alcohol, but soluble in ether.
Heating and drying the bulbs dissipates the volatiles principle, and
the acridity is destroyed.

At a recent meeting of Ohio State Microscopical Society this subject
was again brought up for discussion. It was thought by some that the
raphides in the different plants might vary in chemical composition,
and thus the difference in their action be accounted for. This
question the writer volunteered to answer.

Accordingly, four plants containing raphides were selected, two of
which, the _Calla cassia_ and Indian turnip, were highly acrid, and
two, the _Fuchsia_ and _Tradescantia_, or Wandering Jew, were
perfectly bland to the taste.

A portion of each plant was crushed in a mortar, water or dilute
alcohol was added, the mixture was stirred thoroughly and thrown upon
a fine sieve. By repeated washing with water and decanting a
sufficient amount of the crystals was obtained for examination. From
the calla the crystals were readily secured by this means in a
comparatively pure state. In the case of the Indian turnip the
crystals were contaminated with starch, while the crystals from the
fuschia and tradescantia were embedded in an insoluble mucilage from
which it was found impossible to separate them. The crystals were all
found to be calcium oxalate.

Having determined the identity in chemical composition of the
crystals, it was thought that there might be a difference of form of
the crystals in the various pla