504 Sir G. C. Haughlon on the Commoji Nattire of 



employed with any small fragment or substance that it was 

 desirable to use as a needle. This consisted simply in 

 making a slender needle of wood of the same form as those 

 of metal, by means of which any fragment, though not ex- 

 ceeding the size of the head of a pin, could be attached with 

 wax, and then employed, the same as if it were a needle ot 

 malleable metal, alter being inserted in the little tube of the 

 magnetic needle. The deficient weight of the wooden needle 

 can be made up by twining round it a fine strip of sheet- 

 lead ; and in like manner the metal needles may be made 

 to balance with equal nicety, when too light, by rolling round 

 them a small strip of tin foil ; a necessity that must olten 

 occur, owing to the different densities of the metals employed. 

 All these details are requisite, as the experimenter must in so 

 many cases become his own workman, to meet each particular 

 exigency. 



These needles were urged to the substances by a bar-mag- 

 net, in the same way as in the preceding experiments, and 

 were employed either in measuring the purely magnetic in- 

 tensities or those of non-ferruginous bodies, by using one or 

 the other end as occasion required. The unmagnetic ends 

 were likewise made to connect themselves with substances, 

 for which they had a strong afiinity, by means of the finger 

 instead of a bar-magnet as in the former cases, but to a much 

 greater extent, for it was the only means I had at my com- 

 mand of ascertaining that the junction was made with more 

 than usual readiness, and this result is here marked by the 

 letter^, instead of the signs x x as before. All the other 

 signs formerly used are again employed in similar cases, and 

 it will be seen, perhaps with some surprise, that the mutual 

 affinities of non-ferruginous bodies greatly exceed those of 

 the magnetic needle, there beintj few cases in which the mea- 

 sures did not reach 90 . 



In the preceding branch of this subject, whatever has been 

 said on the importance of giving time for the influence of the 

 needle to take effect, is no longer necessary; and all that is 

 required is to afford the time requisite for oscillation entirely 

 to cease; for here the effects are purely normal, as non-fer- 

 ruginous bodies only are mutually concerned. This result 

 might have been easily anticipated, lor it is now merely 

 natural and spontaneous affinities that are brought into play. 

 Magnetism, in the conmion acceptation of the term, will be 

 seen to be an abnormal and exceptional state, and all the re- 

 sults that proceed from it must partake of the same character. 

 The more powerful therefore the magnet or the loadstone, 

 the more abnormal and exceptional must be its results. 



