Published Sources for
the above Quotations: 
F: 
Opticks," Bk. III 
R: 
In "Webster's Electronic Quotebase," ed. Keith Mohler, 1994. 
A: 
'Principia mathematica', scholium 
N: 
the first law of motion, 'Principia mathematica', A. Motte, transl. 
K: 
The Correspondence of Isaac Newton 


