ACTION OF CAMPHOR ON PLANT LIFE
|*Dr. Benjamin Smith Barton (1796) of Philadelphia wrote: "I put a piece of the woody stem of the Tulip-tree (Liriodendron Tulipifera) with one flower and two leaves..."|
In the year 1798, Benjamin Smith Barton described two experiments as to the stimulant action of camphor on plants. One was made on a Tulip*, which, placed in a solution of camphor, showed vigorous growth, and was longer in withering than other Tulip slips, of the same kind, placed in ordinary water. The other experiment was made on a withering yellow Iris; through treatment with camphor it seemed, for some hours, endowed with new life. Barton came to the conclusion that camphor has a greater action on plants than any other known substance; and he compared its action to that of spirituous liquors, or of opium, on the human body, when taken in certain quantities.
These almost forgotten experiments of Barton's have been repeated, in new forms, by M. Vogel of Munich; and they have a considerable theoretic interest. This author, who has recently communicated his results to the Munich Academy, obtained a homogeneous solution by rubbing camphor with water, and shaking camphor powder in a flask with distilled water. Two branches (alike in size, and similarly conditioned) of a flowering Syringa were then introduced—one into ordinary water, the other into the camphor-water. Considerable difference soon appeared: in twelve hours the branch standing in pure water drooped, and was near withering; the other branch in camphor-water stood upright, and without any sign of withering—some of its buds were even developed; it was not till three days after that this branch began to wither.
In another experiment, a flowering branch of Syringa, which was nearly dead, was placed in the camphor-water, and a marked renewal and recovery was ere long observed, which lasted some time. Frequent repetition of the experiment with branches of Syringa showed the same result in varying degree. The camphor-water seemed to have less effect on vine shoots, and almost none on Sambucus nigra.
The action of camphor on cut branches of living and fully developed plants having thus been established, at least for some species, the idea naturally occurred that camphor must also have an influence on the process of germination of seeds. With this view, several seeds of Lepidium sativum, and various other plants, were taken for treatment, and they were mostly old, as the germinative force in such appears to be weaker than in fresh seeds. The seeds were spread out on some moistened blotting-paper covering a porcelain plate, and a second moist paper was put over them. In all cases the seeds thus treated with ordinary water and with camphor-water were exactly in similar conditions, as regards temperature and access of air.
For the first experiments, seeds of Lepidium sativum, of the years 1869 and 1871, were taken. The entire duration of the germinative force of Lepidium sativum is known to be three years. The seeds of both the years mentioned, treated with ordinary water, showed a very imperfect, retarded germination, while the seeds moistened with camphor-water germinated very soon: those of the year 1869 in twenty-four hours, those of 1871 in seven hours. A similar acceleration of the germinative process has previously been observed in treatment of seeds with chlorine and saline.
A further experiment was made with different kinds of Raphanus sativus major, the seeds being of the year 1866. As the duration of germinative force of this seed is three years, or four at the most, the sowing of these specimens in a garden would, of course, have been thought useless. Treated with camphor-water, however, the seeds germinated in four days, and thus some days earlier than fresh seeds under favorable circumstances.
Seeds of Pisum sativum of the season of 1865 showed in forty hours, under treatment with camphor-water, all the phenomena of the germinative process. Apart from the fact that Pisum sativum, even under the most favorable conditions, first begins to germinate after four or five days, the duration of germination of the seed is two, or at the most three, years; so that seeds of the year 1865 could no longer be sown with advantage.
"With like rapidity germinated seeds of Cucumis sativus under action of camphor-water. In ordinary cultivation of this species of seed in garden ground, not a single grain, out of a large number sown, showed the slightest germinative movement after a long time. The example is thus a striking evidence of the peculiar action of camphor in revival of the germinative force of some species of seeds.
The following flower-seeds were examined in their relation to camphor-water: Schizanthus pinnatus, of the year 1869; Maurandia Barclayana, Coreopsis, Ipomopsis, Senecio elegans, of the year 1860; Silene pendula, Silene amoena, of 1867; Basilicum, Myosotis alpestris, of 1866; Aster species, of 1868; Celosia cristata, of 1867. In all of them a remarkable influence of camphor on the germinative force was perceived. The after development of some of the seeds that were treated with camphor was observed by Dr. Raob, the seeds having been put into the ground. It is interesting to know that the traces of the camphor treatment were here also visible, the young plants showing greater vigor and freshness.
From all these facts, M. Vogel draws the inference that we have in camphor a kind of stimulant for vegetation, capable both of strengthening the force and accelerating the time of vegetation.
There are cases, however, it appears, in which the favorable action of camphor is not observed. Thus, M. Vogel found that Clover-seeds, which in garden soil germinated in twenty-four hours, showed no signs of germination after a longer time, when the earth had previously been mixed with camphor-powder.
As oil of turpentine acts like camphor on the animal organism, M. Vogel made some experiments as to the action of water containing oil of turpentine on plants. The general result was, that this solution also accelerated the germinative process. But there was here, as evidently, an injurious action on the after development of the plants. Even in a few days the progress of the quickly developed seed ceased, and the plant deteriorated.
M. Vogel remarks, in conclusion, that the process of germination, receiving of oxygen, and giving up of carbonic acid, is identical with animal respiration. From the agreement of the vegetable process in the early period of germination with the animal processes, the thought arises that, precisely in reference to this, stimulants are possible whose action resembles the known stimulants of animal life.—Gardener's Chronicle. May 23, 1874, pp. 671-672.
EFFECT OF CAMPHOR WATER ON GERMINATION OF SEEDS. (By A. Burgerstein: Landw. versuchs-stationen, 1888, xxxv, 1.)
Nobbe and Vogel's experiments did not wholly agree, and were repeated by the author, who found that seeds soaked 24 hours in water not only suffered diminution of the germinating percentage, but the growth of the young germs was stunted. Twelve hours even, in camphor water was decidedly unfavorable to germination. From 1-6 hours soaking gave varying results. Vogel ascribed a particular vigor and healthy color to plants as a consequence of soaking the seeds in camphor solution, but this was not observed by the author.—W. E. S.
Influence of Camphor on the Germination of Seeds. By A. Burgerstein (Landw. Versuchs-Stat., 1888, 1-18).— Commencing with a résumé of the work done by Vogel, Wilhelm, and Nobbe, and having pointed out the disagreement which exists between the results obtained, the author passes on to an account of his own experiments in which seeds of different ages and varieties of plants were grown and watered with a solution of camphor, time was also introduced as a factor in these experiments, the results being that camphor-water has an influence on germination, the influence depending on the time. A preliminary soaking in camphor-water has a detrimental effect on all seeds of whatever kind or quality they be, and this influence consists in a retardation of the process of germination, in a reduction in the percentage of germination, and in a reduction in the length of the sprouts during the earlier periods; moreover, absorption of camphor-water for only 12 hours weakens the germinative power. When the period of soaking was only 1 to 12 hours, then out of 27 seeds, 8 were accelerated in their growth, and 9 retarded in germination, whilst the remaining 10 were apparently alike as regards camphor compared with distilled water. No apparent change from normal colour was noticeable—the author cannot agree that camphor revivifies the germinative power of seeds, as Vogel states.—E. W. P.