A COURSE OF EXPERIMENTS, In that CURIOUS and ENTERTAINING Branch of NATURAL PHILOSOPHY.
CALLL'D ELECTRICITY;
Accompanied with LECTURES on the NATURE and PROPERTIES of the ELECTRIC FIRE.
By WILLIAM JOHNSON.
NEW-YORK:
Printed by H. GAINE, at the Bible and Crown, in Hanover-Square, 1765.
[Page] As the Knowledge of Nature tends to enlarge the human Mind, and give us more noble and exalted Ideas of the GOD OF NATURE; it is presumed this Course will meet with Encouragement, as a rational and agreeable Entertainment.
LECTURE I.
I. OF ELECTRICITY IN GENERAL, with some Account of its Discovery.
II. Experiments, shewing that the electric Fire, commonly produced by the Friction of Glass, is not created by that Friction.
III. That it is not extracted out of the Substance of the Glass.
IV. That it is not collected from the Circumambient Air: But,
V. That it is attracted by the excited Glass from the Earth, by Means of intermediate conducting Matter; the whole Tarraqueous Globe, and every Thing thereon, possessing a large Portion of it, commonly called the natural Quantity.
VI. That our Bodies contain enough of it at all Times, to set an House on Fire.
VII. That it has, when in a State of Rest, no sensible Heat.
[Page 4] VIII. That, by its violent Motion in passing through other Bodies, it produces a very intense Degree of Heat. Both these Propositions will be proved by a very accurate Thermometer, of a new Construction.
IX. That it is not the same with common or culinary Fire.
X. That it will live or subsist in Water, as well as in any other Matter; and Sparks may be seen, and felt, rising out of cold Water, or even Ice, that will kindle up a burning Flame.
XI. That it is an extremely subtle Fluid, passing thro' so dense a Body as Metal, with the greatest Facility; even more readily than through any other Matter we are acquainted with.
XII. That some Bodies electrise positively, or increase the natural Quantities in Bodies approaching them, whilst others electrise negatively, or diminish it.
XIII. That the same Body, under different Circumstances, may be made to electrise both positively and negatively.
XIV. That the electric Fire is a simple Homogine Body, and not of two distinct Kinds, as some have imagined.
[Page 5] XV. That Bodies, having only their na [...] Quantity, neither attract nor repel each o [...]
XVI. That Bodies, having their natural Quantity equally encreased or diminished, se [...]mutually to repel each other.
XVII. That this is not a real Repulsion, but apparent only; there being no Repulsion between electrised Bodies.
XVIII. That Bodies having different Quantities, in Proportion to their Magnitudes, attract each other; and the greater the Difference, the stronger the attraction.
XIX. That different Quantities, in separate Bodies, may be reduced to an Equality, by Means of Metal, in the Form of a slender sharp Point, more readily, and at a greater Distance, than in any other Form.
XX. A surprizing Property of an electric Atmosphere, whereby Bodies may be electrised, both plus and minus, by the same Glass, and same Friction.
XXI. An artificial Spider, animated by the electric Fire, so as to act like a live one.
XXII. A new Property discovered in electrised Points, by Means of which will be exhibited a Sort of electrical Horse-Race.
[Page 6] XXIII. A Shower of electrised Sand, whereby one of the Phaenomena of Thunder-Storms is explained.
XXIV. Electrised Money, which scarce any one will take when offer'd.
XXV. The Salute repulsed, or Fire darting from a Lady's Lips or Cheek, so that she may defy any Gentleman to salute her.
XXVI. Spirits kindled by Fire darting from Ladies Eyes, (without a Metaphor.)
XXVII. A diverting Experiment, which cannot well be understood, but by those who try it.
XXVIII. A Battery of seven Guns, fired by a Spark issuing from a Person's Finger.
LECTURE II.
I. A Description and Explanation of the famous Leyden Experiment or electrised Phial, which is the Foundation of most of the Improvements, which have since been made in Electricity.
[Page 7] II. An empty Bottle performing the Leyden Experiment, without having any non-electric Matter communicating with its inner Surface.
III. The amazing Force of the electric Fire, shewn by its passing thro' a Number of Bodies at the same Time.
IV. The electric Fire shewn to be the same with Lightning, from the Simularity of Appearance.
V. A bright Flash of real Lightning darting from a painted Cloud, so as to give the most beautiful and natural Representation of a real Thunder-Storm.
VI. The Cause and Effects of Lightning explain'd.
VII. The electric Element shewn to be real Lightning, from the Simularity of its Effects in tearing and rending Bodies thro' which it passes.
VIII.—In the instantaneous Destruction of Animal Life.
IX&X.—In melting Metal in the Twinkling of an Eye, with the most intense Degree of Heat.
XI. An Experiment, shewing why Thunder Clouds float lower in the Air than other Clouds do; and why Eminences are most frequently struck by Lightning.
XII.—Why we have Thunder more frequent in Summer than in Winter.
[Page 8] XIII. An Experiment, shewing how to avert the Course of a Flash of Lightning from Buildings, Ships, &c. so as to prevent it from doing them the least Damage.
XIV.—Shewing what Part of a House or Chamber, not properly secured against Lightning, is safe to remain in during a Gust, or in Case the House should be struck by Lightning.
XV.—Shewing a probable Method of intirely preventing the impending Stroke of Lightning.
XVI. The endeavouring to guard against Lightning in the Manner proposed, shown not to be chargeable with Presumption, nor inconsistent with any of the Principles of natural or revealed Religion.
XVII. The Manner of erecting an Apparatus in Houses for making Experiments on the Positive and Negative State of the electric Fluid in the Clouds in Thunder Storms, &c. shewn by an Experiment, with an exact Representation in Minature, of such an Apparatus.
XVIII. A Battery of seven Guns, fired by a Spark, passing through cold Water.