126 



so small and so delicately framed, that a fly with it's 

 wing would cover it ; and a little ivory ship of the 

 same dimensions : the second formed ants and other 

 little animals out of ivory, which were so extremely 

 small, that their component parts were scarcely to be 

 distinguished. He says also in the same place, that 

 one of those artists wrote a distich in golden letters, 

 which he enclosed in the rind of a grain of corn, 



13. It is natural here to inquire, whether in such 

 undertakings as our best artists cannot accomplish, 

 without the assistance of microscopes, the ancients 

 had not any such aid ; and the result of this research 

 will be, that they had several ways of helping the 

 sight, of strengthening it, and of magnifying small 

 objects. Jamblichus says of Pythagoras, that he ap- 

 plied himself to iind out instruments as efficacious to 

 aid the hearing, as a rule, or square, or even optic 

 glasses, were to the sight. Plutarch speaks of ma 

 thematical instruments, which Archimedes made usa 

 of, to manifest to the eye the largeness of the sun ; 

 which may be meant of telescopes. Aulus Gellius, 

 having spoken of mirrors that multiplied objects, 

 makes mention of those which inverted them ; and 

 these of course must be concave or convex glas- 

 S9S. Pliny says, that in his time artificers made 

 use of emeralds toassist their sight, in works that re* 

 quired a nice eye ; and, to prevent us from thinking 

 that it w r as on account of it's green colour only that 

 they had recourse to it, he adds, that they were made 

 concave, the better to collect the visual rays ; and 

 that Nero made use of them in viewing the combats 

 of the gladiators. In short, Seneca is very full and 

 clear upon this head, when he says, that the smallest 

 characters in writing, even such afc almost entirely 

 escape the naked eye, may easily be brought to view, 

 by means of a little glass-ball filled with water, which 

 had all the effect of a microscope, in rendering them 

 large and clear : and indeed this was the very sort of 

 microscope that Mr. Gray made use of in his obser- 



