314 o« ^^^ study of natural history. -^ug. 28. 



you have never taken the trouble of inspecting theni 

 narrc wlj. 



Mr Melville, a young Scrichman of uncommon 

 genius*, was struck with the appearance, and ap- 

 plied his attention to the investigation of it. 



He discovered that the lustre of the drop is ow- 

 ing to its copious reflection of light, from the flat- 

 , tened part of its surface, contiguous to the plant ; 

 and that when the drop rolls ovtr a part which has 

 been wetted, it instantly loses all its brightnefs, 

 the green leaf being seen throiigh it. 



From these two observations he concluded, that 

 the drop does not really touch the plant, whilst it 

 retains its quicksilver like appearance, but is sus- 

 pended by the force of a repulsive power. 



For there could not be any copious reflection of 

 white light, from its under surface, unlefs there 

 was a real interval between it and the plant. And 

 if no contact be supposed, it is easy to account for 

 the wonderful volubility of the drop, and why no 

 traces of moisture are left wherever it rolls. 



Now this, my dear Alathea, explains how the fine- 

 ly polilhed needle I formerly mentioned is m "e to 

 swim upon water without touching it; and how such 

 a trivial circumstance fliould have led to one ot the 

 most important improvements in the world. 



Whei. the late Sir John Pringle and Dr Benjamini 

 Franklin were travelling together in Holland, they 

 remarked that the track schuyt or barge in one of 



* Autlior of som most -ngenious tracts, w ho deserves to be merit 

 tioned in a 1 iographi<i Scotic::. 



