NEW CONCEPTIONS IN SCIENCE 



Rayleigh, the English physicist, who presents the 

 noteworthy paradox of a great man of science and 

 a nobleman to the peerage born, not raised. If you 

 will take dry camphor and powder it, and drop it 

 in pure water, the particles will begin to scurry 

 about in every direction. Under a microscope it is 

 very gay. But a trace of oil spread over the sur- 

 face of the water suffices to bring all the particles to 

 a stand-still. Lord Rayleigh had the curiosity to 

 measure accurately the thickness of the thinnest 

 layer of oil that would do this. Knowing the size 

 or volume of the drop of oil needful, and knowing 

 the surface over which it spread, he could readily 

 calculate its thickness. He found it could not be 

 more than 1.6 /LC/I. 



Professor Rontgen, famous as the discoverer of 

 the X-rays, has gone still further. Using another 

 test for continuity, he produced a layer of oil not 

 more than half a micro-micron thick (0.56 /i/u). A 

 step more was taken by Professor Warburg, of 

 Berlin, when he succeeded in weighing the invisi- 

 ble layer of water vapor which condenses on a very 

 dry glass plate in moderately moist air. From its 

 weight it took but a moment to compute that the 

 layers could not be more than 0.2 /u/u thick that 

 is, about half a million times thinner than thin 

 writing-paper. 



Whether this layer of water is continuous or not, 

 no 



