CONNECTION OF ELECTEICITY AND MAGNETISM. 257 



tact, I remove the weights. The rings contract, and several of them 

 vanish at the center. lISTow, it is jjossible to bring two pieces of glass so 

 close together that they will not tend to separate at all, but adhere 

 together so firmly that, when torn asunder, the glass will break, not at 

 the surface of contact, but at some other place. The glasses must then 

 be many degrees nearer than when in mere optical contact. 



Thus we have shown that bodies begin to press against each other 

 while still at a measurable distance, and that even when pressed 

 together with great force they are not in absolute contact, but may be 

 brought nearer still, and that by many degrees. 



Why, then, say the advocates of direct action, should we continue to 

 maintain the doctrine, founded only on the rough experience of a pre- 

 scientiflc age, that matter cannot act where it is not, instead of admit- 

 ting that all the facts from which our ancestors concluded that contact, 

 is essential to action were in reality cases of action at a distance, the 

 distance being too small to be measured by their imperfect means of 

 observation ? 



If we are ever to discover the laws of nature, we must do so by 

 obtaining the most accurate acquaintance with the facts of nature, and 

 not by dressing up in philosophical language the loose opinions of men 

 who had no knowledge of the facts which throw most light on these 

 laws. And as for those who introduce ethereal or other media, to 

 account for these actions, without any direct evidence of the existence 

 of such media, or any clear understanding of how the media do their 

 work, and who fill all space three and four times over with ethers of 

 different sorts, why the less these men talk about their philosophical 

 scruples about admitting action at a distance the better. 



If the progress of science were regulated by Newton's first law of 

 motion, it would be easy to cultivate opinions in advance of the age. 

 We should only have to compare the science of to-day with that of fifty 

 years ago ; and by producing, in the geometrical sense, the line of 

 progress, we should obtain the science of fifty years hence. 



The progress of science in ISTewton's time consisted in getting rid of 

 the celestial machinery with which generations of astronomers had 

 incumbered the heavens, and thus " sweeping cobwebs off the sky." 



Though the planets had already got rid of their crystal spheres, they 

 were still swimming in the vortices of Descartes. Magnets were sur- 

 rounded by effluvia, and electrified bodies by atmospheres, the properties 

 of which resembled in no respect those of ordinary effluvia and atmos- 

 pheres. 



When Newton demonstrated that the force which acts on each of the 

 heavenly bodies depends on its relative position with respect to the 

 other bodies, the new theory met with violent opposition from the 

 advanced philosophers of the day, who described the doctrine of 

 gravitation as a return to the exploded method of explaining every- 

 thing by occult causes, attractive virtues, and the like. 

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