DESiaiT VERSUS NECESSITY. 81 



combination, form, or action, around liim. lie has 

 heard it said that the chance arrangement of two pairs 

 of spectacles, in the shop of a Dutch optician, gave the 

 direction for constructing the first telescope. Possibly, 

 in time, say a few geological ages, it might in some 

 optician's shop have brought about a combination of 

 flint and crown glass which, together, should have been 

 achromatic. But the space between the humors of the 

 eye is not an optician's shop where object-glasses of all 

 kinds, shapes, and sizes, are placed by chance, in all 

 manner of relations and positions. On the hypothesis 

 under which our skeptic is making his examination — 

 the eye having been completed in all but the formation 

 of the lens — the place which the lens occupies when 

 completed was filled with parts of the humors and 

 plane membrane, homogeneous in texture and surface, 

 presenting, therefore, neither the variety of the mate- 

 rials nor forms which are contained in the optician's 

 shop for chance to make its combinations with. How, 

 then, could it be cast of a combination not before used, 

 and fashioned to a shape different from that before 

 known, and placed in exact combination wdth all the 

 parts before enumerated, with many others not even 

 mentioned ? He sees no parallelism of condition, then, 

 by which chance could act in forming a crystalline 

 lens, which answers to the condition of an optician's 

 shop, where it might be possible in many ages for 

 chance to combine existino: forms into an achromatic 

 object-glass. 



Considering, therefore, the eje, thus completed and 

 placed in its bony case and provided with its muscles, 

 its lids, its tear-ducts, and all its other elaborate and 



