Fifthly. The corn and grasses contain sufficient potash to form glass with their flint. A very pretty experiment may be made on these plants with the blowpipe. If you take a straw of wheat, barley, or hay, and burn it, beginning at the top, and heating the ashes with a blue flame, you will obtain a perfect globule of hard glass, fit for microscopic discovery."
The circumstance, that all canes, as well as straws and hollow grasses, have an epidermis of silex, is one of the most singular facts in nature. Mr. Davy, in another place, has stated the advantages arising to this class of vegetables, from their stony external concretion: namely, "the defence it offers from humidity; the shield which it presents to the assaults of insects; and the strength and stability that it administers to plants, which, from being hollow, without this support, would be less perfectly enabled to resist the effect of storms.
Those canes which are not hollow, are long and slender, and from wanting the power to sustain themselves, come usually in contact with the ground, when they would speedily decay, from moisture, but from the impenetrable coat of mail with which nature has furnished them. But questions still arise for future investigators. How came the matter of flint to invest those plants which most need it, and not others? Whence does this silex come? Is it derived from the air, or from water, or from the earth? That it emanates from the atmosphere is wholly inadmissible. If the silex proceed from water, where is the proof? and how is the superficial deposit effected? Also, as silex is not a constituent part of water, if incorporated at all, it can be held only in solution. By what law is this solution produced, so that the law of gravity should be suspended? If the silex be derived from the earth, by what vessels is it conveyed to the surface of the plants? and, in addition, if earth be its source, how is it that earth-seeking, and hollow plants, with their epidermis of silex, should arise in soils that are not silicious? being equally predominant, whether the soil be calcareous, argillaceous, or loamy. The decomposition of decayed animal and vegetable substances, doubtless composes the richegt superficial mould; but this soil, so favorable for vegetation, gives the reed as much silex, but no more, in proportion to the size of the stalk, than the same plants growing in mountainous districts, and primitive soils. It is to be regretted, that the solution of these questions, with others that might be enumerated, had not occupied the profoundly investigating spirit of Mr. Davy; but which subjects now offer an ample scope for other philosophical speculators.
It is a demonstrative confirmation of the accuracy of Mr. Davy's reasoning, that a few years ago, after the burning of a large mow, in the neighbourhood of Bristol, a stratum of pure, compact, vitrified silex appeared at the bottom, forming one continuous sheet, nearly an inch in thickness. I secured a portion, which, with a steel, produced an abundance of bright sparks.
Upon Mr. Coleridge's return from the north, to Bristol, where he meant to make some little stay, I felt peculiar pleasure in introducing him to young Mr. Davy. The interview was mutually agreeable, and that which does not often occur, notwithstanding their raised expectations, each, afterward, in referring to the other, expressed to me the opinion, that his anticipations had been surpassed. They frequently met each other under my roof, and their conversations were often brilliant; intermixed, occasionally, with references to the scenes of their past lives.
Mr. Davy told of a Cornish young man, of philosophical habits, who had adopted the opinion that a firm mind might endure in silence, any degree of pain: showing the supremacy of "mind over matter." His theory once met with an unexpected confutation. He had gone one morning to bathe in Mount's Bay, and as he bathed, a crab griped his toe, when the young philosopher roared loud enough to be heard at Penzance.[74]
Mr. Coleridge related the following occurrence, which he received from his American friend, Mr. Alston, illustrating the effect produced on a young man, at Cambridge University, near Boston, from a fancied apparition. "A certain youth," he said, "took it into his head to convert a Tom-Painish companion of his, by appearing as a ghost before him. He accordingly dressed himself in the usual way, having previously extracted the ball from the pistol which always lay near the head of his friend's bed. Upon first awaking and seeing the apparition, A. the youth who was to be frightened, suspecting a trick, very coolly looked his companion, the ghost, in the face, and said, 'I know you. This is a good joke, but you see I am not frightened. Now you may vanish.' The ghost stood still. 'Come,' said A. 'that is enough. I shall get angry. Away!' Still the ghost moved not. Exclaimed A. 'If you do not in one minute go away, I will shoot you.' He waited the time, deliberately levelled his pistol, fired, and with a scream at the motionless immobility of the figure, was convinced it was a real ghost—became convulsed, and from the fright, afterwards died."
Mr. Coleridge told also of his reception at an Hessian village, after his visit to the Hartz mountains, and the Brocken. Their party consisted of himself, Mr. Carlyon, and the two Mr. Parrys. (sons of Dr. Parry, of Bath—one of them the Arctic explorer). The four pedestrians entered the village late of an evening, and repaired to the chief ale-house, wearied with a hard day's journey, in order to be refreshed and to rest for the night. The large room contained many of the neighbouring peasants. "What can we have to eat?" said Mr. Coleridge. "Nothing," was the reply. "Can we have beds?" "No," answered the master of the house. "Can we have some straw on which to lie?" "None, none," was the reply. On which Mr. Coleridge cried out, "Are the Hessians Christians?" To have their Christianity doubted, was an insufferable insult, and to prove their religion, one man in a rage, hurled a log of wood at Mr. C., which, if it had struck him, would have laid him prostrate! But more effectually to prove that they were Christians, "good and true," the men, in fierce array, now marched up, and roughly drove the saucy Englanders out of the house, to get lodgings where they could. From the extreme wrath of the insulted peasants, the travellers were apprehensive of some worse assault; and hurrying out of the village, weary, and hunger-smitten, bivouacked under a tree, determined never again to question a Hessian's Christianity, even under the gallows.
On one occasion, Mr. Coleridge entered into some of his college scenes, to one of which I may here refer. He said that, perhaps, it was culpable in him not to have paid more attention to his dress than he did when at the University, but the great excluded the little. He said that he was once walking through a street in Cambridge, leaning on the arms of two silk gowns, when his own habiliments formed rather a ludicrous contrast. His cap had the merit of having once been new; and some untoward rents in his gown, which he had a month before intended to get mended, left a strong tendency, in some of its posterior parts, to trail along the ground in the form, commonly called "tatters." The three friends were settling the exact site of Troy, or some other equally momentous subject, when they were passed by two spruce gownsmen, one of whom said to the other, which just caught the ear of Mr. C., "That sloven thinks he can hide his ribbons by the gowns of his companions." Mr. C. darted an appalling glance at him, and passed on. He now learned the name, and acquired some particulars respecting the young man who had offended him, and hastened home to exercise his Juvenallian talent.
The next day he gave his satire to a friend, to show it to the young man, who became quite alarmed at the mistake he had made, and also at the ominous words, "He who wrote this can write more." The cauldron might boil over with fresh "bubble, bubble, toil and trouble." There was no time to lose. He therefore immediately proceeded to Mr. C.'s chambers; apologized for his inconsiderate expressions; thought him to have been some "rough colt," from the country, again begged his pardon, and received the hand of reconciliation. This young, miscalculating Cantabrigian, now became one of Mr. C.'s warmest friends, and rose to eminence.[75]