_To the Editor of the Scientific American:_
Mr. Charles Williams, of Winoa, Ohio, has written a letter to that
veteran botanist, Humphrey Marshall, of Chester county, Pa., on the
subject of the abovenamed plant, and my opinion concerning it has been
asked for. Seeds of this plant were obtained by citizens of Boston,
who had snow brought from the White Mountains and from the coast of
Labrador, and who stated that they have "now the most unbounded
satisfaction and pleasure of announcing that all signs are favorable
to the realization of their fondest hopes." This wonderful plant, it
seems, was found amid the perpetual snows of the northern boundaries
of Siberia, in 1863, by Count Swinoskoff, the eminent Russian
botanist, and it was by him cultivated at St. Petersburgh. The account
sent me is very vague, and is evidently not from the pen of a
botanist. It is stated that it comes forth on the first day of the
year, grows to the height of three feet, and flowers on the third day.
It continues in bloom for twenty-four hours, then dissolves itself,
being of the finest snow; it has a stalk one inch in diameter, and
leaves, three in number, 1½ inches wide, covered with infinitesimal
frost or snow cones. The flower is of the shape of a star, with petals
3 inches long and ½ inch wide at the broadest part, forming a
basketwork of frost. The seeds are like a pin's head. This is about
all that can be gleaned from the description, and is by no means
satisfactory. Allow me to present my humble views of an analogous
discovery of frostwork on December 6, 1856, in a sandy loam in Chester
county, Pa., near the Paoli monument. In the _Horticultural Journal_
of Philadelphia, then edited by J. Jay Smith (New Series, volume vii.,
page 73, 1857), an account was published of my observations then.
These I have since more fully confirmed. The common dittany (cunila
Mariana) is frequently met with in December, with the base of the stem
surrounded with shellwork of ice, of a pearly whiteness. Dr.
Darlington, in his "Flora Cestrica" published in 1853, page 199, under
the article cunila, observes: "In the beginning of winter, after a
rain, very curious ribbons of ice may be observed, attached to the
base of the stems, produced, I presume, by the moisture of the earth
rising in the dead stems by capillary attraction, and then being
gradually forced out horizontally, through a slit, by the process of
freezing. The same phenomenon has been observed in other plants. See
observations on _helianthemum_, page 27." Had the doctor given a more
extended investigation, I fancy he would have agreed with me as to the
cause. I found hundreds of diversified specimens. I am not aware that
it was after a rain, but I took up a number of the plants, and always
found a vigorous scaly root bud, undergoing development at this early
season under ground, to produce a new stem the following spring. I
came to the conclusion that, as the temperature was below freezing and
snow was on the ground, the expanding bud, in close proximity to the
surface, gave out sufficient caloric or warmth to generate vapor from
the moist soil. This vapor rising around the stem of the plant, and
attracted by it, becomes congealed into what we term hoar-frost, in
numerous forms; some like shellwork, others like tulips, with radiated
petals, variously contorted, and often as symmetrical as snowflake
crystals.
[Illustration: Root-bud and frost-flower of the Cunila Mariana
(Maryland Dittany). A, the developing or budding root. B, the old stem
of the previous year. C, the congealed vapor or hoarfrost, forming the
first flower of various shapes.]
That plants in germinating have the power of generating heat was
proved by Mr. Hunter and by Lamarck. Experiments of Hales and Du Hamel
show that vegetation is not wholly suspended, however cold it may be;
and that there is a regular and gradual progress till the returning
warmth of spring gives a greater degree of velocity to the juices,
rendering their development more vigorous and apparent. If the
crystallization takes place when the air is calm, the crystals will be
regularly formed; otherwise, when windy, I have seen them like a shell
within a shell, very thin, of a pearly whiteness. Professor Tyndall
has shown in a very beautiful manner that ice is but an agglomeration
of snow crystals: the transparency of the former being due to the
expulsion of the air, entrapped in and causing the whiteness and
opacity of the latter. There is a formation called the snow plant of
California, which arises to some height, and has been compared to
various things, a fountain convoluted and enlarged above, a
crystallized small bushy shrub, etc.; but on closer inquiry, I have
failed as yet to get any definite ideas to its true character. Some
bulbs in the soil might cause such formations by the congelation of
vapor deposited successively upon itself, or the stems of the previous
year's growth yet remaining, and thus give them a sheathing of
frosting.
The shape of a star is common in snow crystals, which we all know
assume the most beautiful forms, and which are illustrated in various
publications. The eminent botanist Count Swinoskoff should give us
some clue as to the genus or character of the plant, the flower of
which, we are told, melted away on being touched, and as to the
stamens, the diamond seeds like a pin's head, etc. The whole needs
further explanation.
I trust those Bostonians who are in such hope will edify the public as
to the final result of their experiment. What has that veteran in
botany, Dr. Asa Gray, to say about it? Let some one well qualified
tell us more about this frost flower of Russia.
J. Stauffer.
Lancaster, Pa.
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