Bury St. Edmund's, Jan. 14.
IN answer to C.L. (Vol. LXXXIX. ii. p. 518) inquiring the "best mode of producing germination in exotic seeds," and feeling a strong desire to know the result of chemical experiments, as connected with Botany, I beg to refer your numerous readers to the following quotation from "Principles of Botany and of Vegetable Physiology," by Professor Willdenow, "Edin. 1811."
"It has long been known that every plant affects its own particular soil, and that on this account seeds do not germinate in all kinds of soil; at least they soon decay in a disadvantageous one. Various trials have been made to make seeds germinate in various matters, different from the usual earths. Sukkow made plants grow in pounded fluar of lime and barytes. Bonnet made plants grow in saw dust, slips of paper, cotton, and even an old book. That cress (lepidium sativum) germinates upon a piece of woollen cloth, is a well-known fact. M. Humboldt's experiments to make seeds germinate in metallic oxyds, especially the red oxyd of lead, red massicot, &c. are more instructive. In powder of coal and sulphur, seeds germinated likewise very well. He found that oxygen proved an extreme stimulus to plants, and that without it they never can be brought to germinate. On this account germination went on quickly in metallic oxyds, especially in minium. In oil, on the contrary, carbon, hydrogen, in the filings of lead, iron and copper, as well as in powdered molybdene and in alkalis, no one seed germinated. It soon occurred to him, that with oxygen as a stimulant, he might forcibly make seeds germinate faster; and he actually found, that at the temperature of 20° Reaum. [77°F] all seeds vegetated most rapidly when steeped in oxymuriatic acid. One instance alone will suffice. The seeds of Lepidium sativum germinated after six or seven hours, when put into oxymuriatic acid; whereas, when lying in common water, they required from 36 to 38 hours. In a letter, dated Feb. 1801, he writes to me, that in Vienna they derived much benefit from the discovery of this fact, and that seeds, 20 or 30 years old, brought from the Bahama Islands, Madagascar, &c. which constantly refused to germinate, very readily in this way vegetated and produced plants which grew up very successfully. [The Mimosa scandens, which as yet is not to be found in any botanic garden, grew very well with this acid.] As every gardener cannot obtain the oxymuriatic acid, Mr. Humboldt proposes a very easy method to procure it without difficulty. He took a cubic inch of water, a tea-spoonful of common muriatic acid, two tea-spoonfuls of oxyd of manganese; mixed it, and placed the seeds in them. The whole was now allowed to digest with a heat of 18-30 Reaum. [72.5°F-99.5°F]. In this the seeds germinated excellently; but it is necessary to take the seeds out as soon as the corkle [corcle: embryo, germ] appears. That the seeds are not injured by the acid, is proved by the many plants which have been treated in this way, under the inspection of Mr. Jacquin, and in which vegetation went on extremely well.
"It is the oxygen of the atmosphere which stimulates the seeds to germination; and this explains at once the experiment of Mr. Achard, why plants vegetate faster in very compressed air, than in air in its common state.
"Besides oxygen, ammonia favours the germination of seeds: hence, they germinate almost immediately, when placed in dung, which, therefore, serves as manure. Cow-dung, we know, consists of muriatic acid and ammonia. In fluids which contain no oxygen, seeds will not germinate. Thus, they never germinate in oil, which consists of hydrogen and carbon."
preceding observations may induce some of your correspondents to exercise their
patience and ability towards effecting the germination of foreign seeds; in
which case, should success attend their labours, a statement of the names of
such exotics, (through your interesting publication) would be highly gratifying
Yours, &c. H.S.N.