This could not well be otherwise; for beyond a contrivance like your Leyden jar, for collecting “air electricity,” no means of collecting, still less concentrating, electricity of any kind then existed.

The belief once generally entertained was, that there were but two electricities, or rather two varieties of the same electricity, one repellent and the other attractive, answering in a measure to your terms of positive and negative.  Some, indeed, thought that several different kinds existed; but the renowned electricians—­truly great men, for they had opened the gates of science—­proclaimed that all electricities were in reality one and the same, modified only by accidents.

They referred to certain phenomena always resembling each other in whatever way the electricity producing them might be generated; and they argued, with an appearance of truth, that the electricity which produced these similar phenomena must be one and the same:  for, asked they, are not like causes indicated by like effects?  The principle was right, but, as was subsequently shown, the application and the conclusion were wrong.  The error had arisen from the fact that electricities of every kind possess certain properties in common:  thus, air electricity enters into the composition of them all.  These common properties produce phenomena varying only in degree, but so similar to each other that, in the absence of further knowledge, the electricians concluded that their theory was correct, and, in consequence, many valuable discoveries were retarded for centuries.

MANY KINDS OF ELECTRICITY.

In my reign, however, tangible and visible proofs established beyond doubt that every kind of body and substance, whether animate or inanimate, contains an electricity of its own.

Although all electricities contain air electricity, and are similar in some other respects, yet each differs from all others by reason of some properties peculiar to itself, the species being different, though the genus is the same.  As in the case of the blood of animals, which is called by the common name of blood in spite of material differences, when the species is different, so we have a generic name for all electricities, a term signifying “A spark of Heaven power.”

Some electricities are diffused and attenuated; some are concentrated; others are so tenacious of the body to which they belong that they are all but steadfast.  Some are sympathetic; some antipathetic, attracting or repelling each other; some mingle gently; others, when brought into contact, cause violent explosions.

DRAWING OUT AND CONCENTRATING ELECTRICITIES FOR USE.

We discovered the means of drawing out the various electricities from the body to which they are appetent, and of concentrating and preserving them for use.