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Show 80 DARWINIAN A. that more then a hundred years ago Mr. Dollond having found out, after many experiments, that some kinds of glass have the power of dispersing light, for each de-· gree of its refraction, much more than other ldnds, and that on the discovery of this fact he contrived to make telescopes in which he passed· the light through two obJ' ect-O'lasses successively, one of which he made of • b crown and one of flint glass, so ground and adapted to each other that the greater dispersion produced by the substance of one should be corrected by the smaller dispersion of the other. This contrivance corrected entirely the colored images which had rendered all previ<?us telescopes very imperfect. He finds in this invention all the elements of design, as it appeared in the thought. and action of a human designer. First, conjecture of certain laws or facts in optics. Then, experiment proving these laws or facts. Then, the contrivance and formation of an instrument by which those laws or facts must produce a certain sought result. Thus enlightened, our skeptic turns to his crystalline lens to see if he can discover the work of a Dollond in this. :Here he finds that an eye, having a crystalline lens placed betw.een the humors, not only refracts the light more than it would be refracted by the humors ~lone, but that, in this combination of humors and lens, the colors are as completely corrected as in the combination of Dollond's telescope. Can it be that there was no design, no designer, directing the powers of life in the formation of this wonderful organ~ Our skeptic is aware that, in the arts of man, great aid has been, sometimes, given by chance, that is, by th~ artist or workman observing some fortuitous DESIGN VERSUS NECESSITY. 81 combination, form, or action, around him. He has heard it said that the chance arrangement of two pairs of spectacles, in the shop of a J:?uteh optician, gave the direction for constructing the first telescope. Possibly, in ~ime, 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 examinationthe 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 materials nor forms which are contained in the optician's shop for chance to make it~ 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 with 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 existing forms into an achromatic object-glass. Considering, therefore, the eye thus completed and placed in its bony case and provided with its muscles, its lids, its tear-ducts, and all its other elaborate and |