On the electric column, and aerial electroscope / by J. A. De Luc.

  • Luc, J. A. de (Jean André), 1727-1817.
Date:
1812
Catalogue details

Licence: Public Domain Mark

Credit: On the electric column, and aerial electroscope / by J. A. De Luc. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    12/17 page 11
    There is some sort of impediment to the motion of the electric But progres- fluid along the column, probably caused by a reluctance in the sive* zinc plates to part with the superior quantity of electric fluid they must possess when united with copper, to produce their electrical equilibrium The consequence is : that, after having observed the divergence of the gold leaves in both electrometers, if one of the extremities of the column be made to communicate with the ground $ by which the gold leaves fall on this side, and they diverge more on the other side $ it requires a long time, in some cases many hours, for the same divergences to be restored. 15. There is an entertaining experiment, which may lead to Similarity be- some discovery respecting the physiology of vegetables. Each t;on of the of the electrometers of the column may be made to imitate the lumn, and that sensitive plant (mimosa sensitiva :) for, as the contact of °ne sensitive of the extremities of the column produces the fall of the gold leaves on this side, which rise slowly ; the contact of the sen- sitive plant makes its leaves fall, and they also rise slowly. This analogy of slow effects, pointing out some general analogy between their causes, must render us cautious not to assign hastily to some vague property the effects that we may follow distinctly in their process, such as those of the electric column $ for they may lead us, in time, to the discovery of causes, in those phaenomena which now appear the most obscure. 16. The lid part. Sir, of the same paper in your journal, concerns the electric column in its phaenomena as an aerial elec- culation influ- troscope, and contains the observations which I had already enced by some . . , . . . . . . . J external cause, made with that instrument. JLhis class or experiments relates to the opinion of Dr. Maycock, forasmuch as they prove, not only a constant motion of the electric fluid in the column, but that some external cause influences much the rapidity of its motions; an object the explanation of which I had postponed. 17. These changes are seen, when the extremities of the As shown by column are not made to communicate immediately with each tr0SC0pe<i other j but only by the alternate sinkings of a body suspended between them, taking some electric fluid from the positive side, and bringing it back to the negative. Now, the more rapid is the motion of the electric fluid in the column, the more numerous are the sinkings in a given time 5 and the difference
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