Page:Popular Science Monthly Volume 1.djvu/655

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MISCELLANY.
639

he became intoxicated every day, but, once the drunkenness had disappeared, he resumed his usual habits; the other four, on the contrary, exhibited a very remarkable nervous susceptibility. They became restless—listened; the slightest noise caused them to start, whenever the door opened they hastened to cower in the most obscure corner of the hall, leaving in their way a trail of urine; they paid no attention to petting; when one came near them, they bit; if one threatened to strike them, they uttered piercing cries. A short time afterward, hallucinations occurred in two of them. As if pursued by an enemy, they barked violently, they ran wildly in every direction, the head turned back, and biting in the air. Whenever one entered, they crowded against the wall, moaning, crying, trembling in all their limbs. In the middle of the night they began sometimes to howl loudly, to utter doleful cries, and stopped only when one went in with the light.

These attacks of delirium were transient, and occurred regularly toward the end of the state of drunkenness. One of the dogs had hallucinations of a cheerful character, under the immediate influence of alcohol; he appeared affectionate whenever he began to stumble; later, on the contrary, he was indifferent—or, rather, he growled and bit.

These hallucinations, of frequent occurrence during two months of the experiment, became afterward rarer, probably on account of the ingestion of less alcohol.

The author gives the following indications of the stages of hallucination in cases of delirium tremens among men: In the first degree the patient believes he hears abusive language, provocations; he sees thieves, armed persons, animals, or else he hears the voice of his parents, of his friends who call him, who warn him of a danger, who appeal for his help, etc. Stimulated by these incitements, the patient answers, injures, quarrels, runs, rushes off, becomes furious, etc., all which acts tend to develop in him a boisterous condition, a state of mania.

In other circumstances he believes himself to be in prison, before a court of justice; he is accused of various crimes; he believes that he has committed them; he believes that his wife is unfaithful to him, that he is deceived by his friends; he is present at the funeral of his parents, etc. Under the weight of these distressing impressions, he is dull, restless, suspicious; he laments, he becomes terrified, he attempts to escape, sometimes even he meditates homicide or suicide; he presents, in a word, the aspect of a melancholic. Finally, in the most intense form, he believes himself chained at the foot of a scaffold, he has before him the bleeding corpses of his children, every thing is on fire, he is about to be swallowed up, etc. These appearances have astounded, appalled him, he remains motionless, in a complete state of stupor.

The Office of Lightning-Rods.—In his valuable little work on "Lightning-Rods, and how to construct them," Prof. John Phin thus states what the lightning-rod should do:

The function or office of the lightning-rod is twofold. In the first place, it acts as a means whereby the accumulated electricity existing in the atmosphere is silently drawn off, and allowed to pass into the earth, and thus prevent an explosion; and in the second, it acts as a path by which explosions, lightning-flashes, or disruptive discharges (as they are more properly called), may find their way to the earth freely, and thus be carried off without any danger of their acting with mechanical violence, as they are certain to do when made to pass through what are called non-conductors. Experience teaches us that, so long as a discharge of electricity passes off through a wire that is large enough to carry it safely, it does not cause any damage, or give rise to the exhibition of mechanical violence. A spark from the prime conductor of an electrical machine, if passed through a moderately fine wire, does not injure it; if passed through a thick card, it will pierce it; and, if passed through a small block of wood, it will rend it asunder. On the occasion of every thunder-storm, there is a large quantity of electricity to be conveyed from the clouds to the earth, through the air, which is in general a very poor conductor. This electricity always tends to pass by the easiest path, or, as electricians say, the line of least resistance. The resistance of any line may be lessened by various circumstances, such as the presence of hot vapors, as from chimneys, heated hay-stacks in the open field, or heated hay-mows in the barn; the existence of a line of carbonaceous matter, such as exists in a column of smoke; the presence of a tree with its leaves and sap, or of a house with its chimneys; or the fact that the air has been rendered moist by the passage of a shower of rain. So difficult is it, however, to detect the circumstances which render any particular path more easy than others, for the electricity to follow,