of Electrkidj. 99 



philosophical to apply the electric fluid as the cause or 

 power, and elcctricitv to the effect. 



Electricity is ioiind to be of two kinds ; one produced 

 by the excitation cl' glass, and tbmicrly called vitreous : the 

 other by the excitation of resin, and called resinous : — 

 vhctherwe impute these different phaenomena to the action 

 of one or of two fluids, it is convenient to adopt some terms 

 which shall distinguish these different states, if of one 

 fluid ; or the different fluids if two ; as a mean of such 

 distinction, the terms positive and negative may be safely 

 acquiesced in bv all parties, without any precise definition 

 of the sense in which thev ought to be received. The ad- 

 Jierents of Dr. Franklin consider positive as denoting re^ 

 dundancy, — and negative, deficiency. 



When electrical appearances, viz. the attraction of light 

 bodies or sparks, are induced by friction upon any bodv, 

 such bodv is said to be excited. 



Electricity may be produced four ways : — 1. Friction ; ?. 

 Heating and cooling, as is particularly remarkable in the 

 tourmalin ; 3. Melting, or pouring one melted substance 

 into another ; 4. Evaporation : perhaps all these modes may 

 be justly deemed mechanical, and resolve themselves into 

 friction. When electricity is communicated from an excited 

 electric to another body, that body is said to be electrified. 

 I shall first state the series of propositions which I conceive 

 comprises the most prominent and leading features of the 

 Frankhnian theory ; and shall then consider them sepa- 

 rately, adverting to the proofs by which they are supported. 



Prop. 1 . That the phaenomena of electricity are impu- 

 table to the operations of one fluid, peculiar in its nature 

 and properties ; generally invisible ; extremely subtile and 

 elastic ; universally and plentifully diffused through the at- 

 mosphere and other terrestrial substances. 



Prop. 2. That the particles of which this fluid is com-' 

 posed have a strong attraction to other matter, and a strong 

 repulsion between themselves. 



Prop. 3, That this fluid, pursuant to the general law of 

 hydrostatics, will, in a state of rest, be uniformly difliiscd 

 in proportion to the capacity of bodies, and m this state of 

 .uniform distribution will uoduce no effect cognizable by 

 our senses; but that this state of equilibrium is frequently, 

 and may easily be, disturbed by natural or artificial causes. 



Prop. 4. That this flu id moves with various degrees of 



facility through the pores of diflfercnt kinds of matter in 



a certain class of bodies which are capable of transmitting 



^is fluid with facility, . and for that reason called conduc- 



C U tors. 



