bijlitence of Metallic Trailers. 253 



the metallic tractors fhould in a few minutes remove violent 

 pains, as we now know why cantharides and opium will 

 produce oppofite effects : viz. we fhall know but very little 

 about either, excepting_/fl<?7.r." 



Mr. Woodward, profeffor of natural philofophy at Dart- 

 mouth, in a letter alfo on the fame fubjedt, has ftated a 

 number of fuccefsful experiments in pains of the head, face, 

 teeth, and in one cafe of a fprain. 



Dr. Vaughan, a member of the Philadelphia medical 

 fociety, has lately publiflied an ingenious tract onGalvanifm, 

 the object of 'which is to account for the influence of the 

 tractors in removing difeafes. After a citation of numerous 

 experiments made on the nerves and mufcles of animals, he 

 obferves, " If we only take an impartial view of the opera- 

 tions of nature berfelf, and attend diligently to the analytical 

 inveftigations of the aforementioned experimentalifts on this 

 fublime fubjeet, I think the feeptic mult admit that the prin- 

 ciple of nervous energy is a modification of electricity. As 

 fenfation is dependent on this energy, a pleafurable fenfation, 

 or what may be termed a natural or healthy degree thereof, 

 then certainly pain or fuperfenfation can only depend on 

 an accumulation of the electric fluid, or extra degree of 

 energy in the part affected. On this principle the problem 

 admits of eafy folution •, namely, that the metals,- being fuf- 

 ceptible of this fluid, conduct the extia degree of energy to 

 parts where it is diminifhed, or out of the fyftem altogether, 

 refioring the native law of electric equilibrium." 



Drs. Tilton, Baker, Hall, Lord, Brewfter, Dalho, Dyer, 

 Johnfon, Backus, Lee, Willard, Marvin and Gofs, of Ame- 

 rica, have publiflied their approbations of theufe of metallic 

 tractors ; which are in fact only pieces of pointed iron or 

 brafs, &c. How far the attempt of the author to explain 

 their action upon the principles of Galvanifm has been fuc- 

 cefsful, we will not take upon us to determine We (hall 

 only obferve, that were it even demonftrated to be a revival 

 o£ animal maguctitni, if its efficacy be at the Jamc me de. 

 9 mo:yirated t 



