DEATH BY LIGHTNING.
It has been incontrovertibly established by the experiments of modern philosophers, that the phœnomena of electricity are identical with those of thunder and lightning. The human body is alike affected by both; and death, whether it be occasioned by the discharge of an electrical battery, or by that of a thunder cloud, exhibits effects precisely analogous.
Mr. Hunter supposed that when death is thus occasioned, there is an instantaneous and entire annihilation of the vital principle, in every part of the animal machine; and that the muscles are therefore relaxed, and incapable of contraction, that the limbs do not stiffen[[54]], as in other cases of death, nor the blood coagulate, and that the body very speedily runs into a state of putrefaction. The experiments however of Mr. Brodie[[55]] will induce us to pause, and institute farther enquiries before we receive this theory as unexceptionable. It will appear that in the following experiments of this physiologist, an instantaneous extinction of vitality did not take place, but, on the contrary, the functions of the brain were those on which the electric shock exercised its primary influence. An electric battery of six jars having been charged with electricity, the shock was made to pass through a Guinea pig, in the longitudinal direction from the head to the tail: the animal immediately fell on one side, insensible, as if stunned; a convulsive action of the muscles of the extremities was observed, but did not long continue; and the function of respiration was not interrupted. In a few minutes sensibility was restored, and the animal recovered. A shock from a battery of nine jars was then passed in the same manner through another Guinea pig; the animal immediately fell on its side, exhibited a convulsive action of the voluntary muscles of the limbs, but uttered no cries, and although attentively watched, no signs of respiration could be discovered after the shock had passed through it. Three minutes afterwards, Mr. Brodie opened the chest, and found the heart acting with regularity and vigour, about 80 times in a minute, and circulating dark coloured venous blood; the peristaltic motion of the intestines was likewise visible; and the muscles, when made the part of a galvanic circuit, readily contracted. In this experiment, observes Mr. Brodie, it is evident that the electric shock did not destroy the irritability of the muscular fibre, nor did it affect the action of the heart. Death took place precisely in the same manner as from a severe injury of the head; and the animal died, manifestly from the destruction of the functions of the brain; and, in this case, Mr. Brodie has no doubt, but that if the lungs had been artificially inflated, the action of the heart might have been maintained, and the animal probably have been restored to life.
The nature and extent of the injury inflicted by lightning, depend upon the intensity and direction of the electrical discharge, and vary greatly in degree; by far the greater number of flashes are harmless discharges from one cloud to another, and the instances in which it strikes the earth are comparatively rare: when however this does occur, and it directs its course through a human being, it may expend its influence upon the surface, and produce partial or general vesications.[[56]] Sometimes the clothes of the person have been violently rent, and the metallic substances about them melted; or it may pass through the body, without including the clothes, and it may occasion death without injuring the organic structure of any part of the body: or it may pass through only a particular portion of the body, and produce local injury.
But it has happened that persons have been struck when the tempest has appeared to be at a considerable distance; this has been explained by Signor Beccaria, by supposing that it is a discharge of electric fluid from the earth, occasioned by the passing of a cloud that has just before, in the elemental strife, been rendered negatively electric. Lord Stanhope distinguishes such a discharge by the name of the Returning Stroke.[[57]]
As a provision for personal security during a thunder storm, a few precautions are necessary, and we are induced to notice them in this place, as their history is necessarily involved in our enquiries concerning death by lightning. In the open air, shelter ought not to be sought immediately under trees, for should they be struck, such a situation would be attended with the most imminent peril: on the contrary, the distance of twenty or thirty feet from such objects, may be considered as affording a place of safety, for should a discharge take place, they will most likely receive it, and the less elevated bodies will escape. Any surface of water, and even the streamlets that may have resulted from a recent shower should be avoided, for being excellent conductors, the height of a man, when connected with them, is very likely to determine the course of an electrical discharge. The partial conductors, through which the lightning directs its course when it enters a building, are usually the appendages of the walls and partitions; the most secure situation is therefore the middle of the room, and this situation may be rendered still more secure by lying on a hair mattress, or even on a thick woollen hearth rug. The part of every building least likely to receive injury is the middle story, as the lightning does not always pass from the clouds to the earth, but is occasionally discharged from the earth to the clouds, as in the case of the “returning stroke;” hence it is absurd to take refuge in a cellar, as recommended by Dr. Priestley; indeed many instances are on record, in which the basement story has been the only part of a building that has sustained severe injury, the electric charge being divided and weakened as it ascended. Any approach to a fire-place should be particularly avoided, for the chimneys are very likely to determine the course of the lightning; the same caution is necessary with respect to gilt furniture, bell-wires, and moderately extensive surfaces of metal of every description.