I?* Mr. J. Goodman's Researches into the Identity of 



of a more powerful nature, does not generally augment, but 

 rather diminish the amount of the latter*. 



I found that the nncrystalline metals, gold, silver, copper, 

 lead, &c., were unable to develope currents of any appreciable 

 amount (as seen also in the Table), although the heating pro- 

 cess was continued to a considerable degree of intensity. (See 

 37, 38.) 



The experiments adduced show that these latter metals may 

 be simpl}' regarded as conducting media to thermo-electricit}', 

 that they offer no specific resistance to the flow of current, 

 and may therefore be employed either in conjunction with 

 electro-positive or electro-negative metals. 



The results thus arrived at resemble much those evinced 

 by the experiments of Dr. Franklin and others on the tour- 

 maline, in which ordinary electricity was developed by heat 

 alone, save that in this instance the electricity resembles the 

 voltaic fluid, owing no doubt to the want of that complete in- 

 sulation among the molecules of the metals which is afforded 

 by the tourmaline. 



It is remarkable that no polar fluid, or electricity of any 

 kind, is ever developed without the employment of a crystal- 

 line, insulating, or iniperfecdy conducting body; for in vol- 

 taic arrangements [heelicirolt/te is this non-conducl ing medium; 

 in the cases just cited, the tourmaline was the intermediate 

 polar body; in ordinary electricity, the glass cylinder is the 

 non-conducting body, or "electric;" and in thermo and me- 

 chanical electricity (hereafter to be mentioned), the crystalline 

 metals, bismuth, iron, steel, antimony, zinc, &c., are found to 

 be the intervening polar structures, giving rise to these forms 

 of electric fluid. 



The same remarks hold good also with regard to the polar 

 condition and insulating properties (witnessed by the author) 

 of high-pressure steam in the generation of hydro-electric, 

 and to the polarizable quality of steel and iron in electro- 

 magnetic, magneto-electric, and magnetic phaenomena. 



In contemplating the known electrical phtenomena which 

 occur by the contact of dissimilar metals, and the processes 

 of friction, pressure, fracture, vaporization, &c,, and witnessing 

 the effects which heat thus produces upon bismuth, 8:c., I 

 devised the friction of this met.al in a lathe, as a preparatory 

 experiment to some hereinafter contained, in hopes of being 

 able to manifest the continuous transmission of electricity from 



* It WHS found that the crystalline metals, bismuth and antimony, which 

 form the best combination for thermo-electric purposes, are naturally imi- 

 tiially reciprocal metals. Bismuth negative, 4.5°; antimony positive, cur- 

 rent 22|° ; and yet conjoined, they only produced a current of 48°. 



