A letter to Prof. Faraday, on certain theoretical opinions / by R. Hare.

  • Hare, Robert, 1781-1858.
Date:
[1838?]
Catalogue details

Licence: Public Domain Mark

Credit: A letter to Prof. Faraday, on certain theoretical opinions / by R. Hare. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    (See par. 1616.) Must not every particle be excited negatively, if it be excited positively ? Must it not have a negative, as well as a positive pole ? I cannot agree with you in the idea that consistently with the theory which ascribes the phenomena of electricity to one fluid, there can ever be an isolated existence either of the positive or negative state. Agreeably to this theory, any excited space, whether minus or plus, must have an adjoining space relatively in a different state. Between the phenomena of positive and negative excitement there will be no other distinction than that arising from the direction in which the fluid will endeavor to move. If the excited space be positive, it must strive to flow outward; if negative, it will strive to flow inward. When suffl- ciently intense, the direction will be shown by the greater length of the spark, when passing from a small ball to a large one. It is always longer when the small ball is positive, and the large one negative, than when their positions are reversed.* But for any current’it is no less necessary that the pressure should be on one side comparatively minus, than that on the other side, it should be comparatively plus; and this state of the forces must exist whether the current originates from a hiatus before, or from pressure behind. One current cannot differ essen- tially from another, however they may be produced. In paragraph 1330, I have been struck with the following query, “ What then is to separate the principle of these extremes, perfect conduction and perfect insulation, from each other; since the moment we leave the smallest degree of perfection at either extremity, we involve the element of perfection at the opposite ends ?” Might not this query be made with as much reason in the case of motion and rest, between the extremes of which there is an infinity of gradations ? If we are not to confotmd motion with rest, because in proportion as the former is retarded, it differs less from the latter; wherefore should we confound insulation with conduction, because in proportion as the one is less eflicient^ it becomes less remote from the other ? In any case of the intermixture of opposite qualities, may it not be said in the language which you employ “ the moment we * See my Essay on the causes of the diversity in the lengtii of the sparks, erro- neously distinguished as positive and negative, in vol. v, American Philosophical Transactions.