Part 17 (1/2)

In June, 1823, at Moisselles, lightning fell upon a great elm, and striking against an enormous k.n.o.b, rebounded on to a neighbouring elm half its own height, pierced it through and through, s.h.i.+vering it to tatters; the trunk was burst open to the roots, it looked as if it had been bored through from one end to the other by a red-hot bullet that blackened and charred it.

Does it not seem as if the lightning plays with the lives of the trees as with man? It threatens, changes, apparently spares, returns to the charge and finally annihilates. And this sport is accompanied, at times, by inconceivable effects.

But records are still more eloquent than reflections: Nature, in her own mute speech, tells us of a thousand marvels.

Is not the following phenomenon enough to make lightning more mysterious in its fantastic and varied mode of action?

On the 19th of April, lightning struck an oak in the forest of Vibraye (Sarthe), cut this tree, measuring a metre and a half in circ.u.mference, at two-thirds of its height, pulverized the lower parts, strewed the shreds over a circuit of fifty metres, and planted the upper part exactly on the spot from which the trunk had been s.n.a.t.c.hed, with all the rapidity of a flash.

Moreover, the annual concentric circles were separated by the sudden drying up of the sap so effectually, that, the strips only remained welded together where the knots made too great an obstacle to their separation.

How was the lightning able to plant in the earth, with such inconceivable rapidity, the top of the tree where the roots had been?

This is something which no one can explain. It alone is capable of creating such situations.

But it has done better still! Two years later, in 1868, it took the opportunity of playing a good trick on two trees of different species, an English oak and a forest pine, which, without race jealousy, fraternized in the forest of Pont-de-Bussiere (Haute-Vienne). These two trees were about ten yards apart, and were simultaneously hit by the explosive matter, and in the twinkling of an eye, their leaves were changed. The pine needles found themselves on the oak, and the leaves of the oak went to brighten the austerity of the pine with their delicate verdure. There was nothing commonplace about the metamorphosis. Accordingly all the inhabitants went in crowds to the scene of this miracle to contemplate the unusual spectacle of a pine-oak and an oak-pine.

And the unexpected happened: both trees appeared to thrive very well in these new conditions: the pine continued to be agreeably adorned with its festival foliage, whilst the oak agreed perfectly with the sombre needles of the pine.

After such marvels, my readers will not be surprised to learn that lightning sometimes shatters the living wood, or decayed wood, into a thousand morsels without setting it on fire.

For instance, a bundle of f.a.ggots lying on the hearth has been reduced to atoms by lightning, without any trace of combustion being visible.

A fireball fell on a sheaf of barley in the open field without setting it on fire, and buried itself in the ground without doing other further damage.

In certain cases the electric fluid chars wood at varying depths: the blackened layer is often very slight; sometimes, on the contrary, combustion is complete.

As for the leaves, they are unhurt as a rule. When they are attacked they shrivel up; an autumnal shade takes the place of their charming green tints; they turn brown and dry up quickly.

One of the trees in the Champs-elysees having been struck, it was proved that all round it the ground was full of little holes. In two or three places the bark was raised from beneath; the leaves were yellow and shrivelled up as parchment would be by the fire; the upper part remained green. Everything seemed to prove that the lightning came out of the ground.

At other times the same effect may be observed on the leaves, when the trunk and roots are apparently uninjured. It is not unusual to see the tree instantly stripped of its leaves as if by some mysterious power.

The lightning acts also on the roots, as we have seen in the preceding examples. They have been seen uncovered where the ground was much disturbed, torn in strips, or cleft in more or less regular pieces.

We see that lightning does not make more ado about exhaling its baleful breath on the life of plants, than on animals and men. And moreover, that it often strikes these latter with sudden death without leaving a trace of its pa.s.sing, just as sometimes it strikes the trees without leaving any exterior injury. Now and then life is not completely extinguished, and little by little the tree recovers its health. Often the vitality is not changed, one sees the tree which was struck bear fruit as before the catastrophe.

Has it not been a.s.serted that lightning may exert a benign influence on vegetation?

This was the opinion of the ancients.

_A propos_ of this, Pliny said, ”That thunder is rarely heard in winter, and that the great fertility of the soil is due to the frequency of thunder and rain in spring; for the countries where it rains often and in good earnest during the spring, as in the island of Sicily, produce many and excellent fruits.”

It has been proved in our times that the ancients were right in extolling rainwater as nourishment for the products of the earth, and science has discovered the cause to be the presence of great quant.i.ties of nitrogen and ammonia in the thunder-rain and in hail.

Perhaps electricity has a similar effect.

In the neighbourhood of Castres, on April 13, 1781, an old poplar was stripped of its bark in several places. Now, shortly afterwards it burst into leaf, although the neighbouring poplars were much later than it.

The ravages caused in the fields by the electric meteor to forage and vegetables are sometimes considerable. This is especially so with gra.s.s when cut, to hayc.o.c.ks, ricks of straw, barley, etc. We have a collection of records of men or animals who, when leaning against haystacks, were struck.

As a rule the haystack is burnt; sometimes, however, the gra.s.s is simply scattered and thrown to a distance.