Curiosities of Science. 41 



gems in the construction of Microscopes, Sir David Brewster 

 has been met with the objection that they are too expensive for 

 such a purpose ; and, says Sir David, " they certainly are for 

 instruments intended merely to instruct and amuse. But if 

 we desire to make great discoveries, to unfold secrets yet hid 

 in the cells of plants and animals, we must not grudge even a 

 diamond to reveal them. If Mr. Cooper and Sir James South 

 have given a couple of thousand pounds a piece for a refracting 

 telescope, in order to study what have been miscalled * dots ' 

 and ' lumps ' of light on the sky ; and if Lord Rosse has ex- 

 pended far greater sums on a reflecting telescope for analysing 

 what has been called ' sparks of mud and vapour ' encumber- 

 ing the azure purity of the heavens, why should not other phi- 

 losophers open their purse, if they have one, and other noble- 

 men sacrifice some of their household jewels, to resolve the mi- 

 croscopic structures of our own real world, and disclose secrets 

 which the Almighty must have intended that we should know ?" 

 Proceedings of the British Association, 1857. 



THE EYE AND THE BRAIN SEEN THROUGH A MICROSCOPE, 



By a microscopic examination of the retina and optic nerve 

 and the brain, M. Bauer found them to consist of globules of 

 oyfrqth to 4o7K>th of an inch diameter, united by a transparent 

 viscid and coagulable gelatinous fluid. 



MICROSCOPICAL FXAMINATION OF THE HAIR. 



If a hair be drawn between the finger and thumb, from the 

 end to the root, it will be distinctly felt to give a greater resist- 

 ance and a different sensation to that which is experienced 

 when drawn the opposite way : in consequence, if the hair be 

 rubbed between the fingers, it will only move one way (travel- 

 ling in the direction of a line drawn from its termination to its 

 origin from the head or body), so that each extremity may thus 

 be easily distinguished, even in the dark, by the touch alone. 



The mystery is resolved by the achromatic microscope. A 

 hair viewed on a dark ground as an opaque object with a high 

 power, not less than that of a lens of one-thirtieth of an inch 

 focus, and dully illuminated by a cup, the hair is seen to be in- 

 dented with teeth somewhat resembling those of a coarse round 

 rasp, but extremely irregular and rugged : as these incline all 

 in one direction, like those of a common file, viz. from the 

 origin of the hair towards its extremity, it sufficiently explains 

 the above singular property. 



This is a singular proof of the acuteness of the sense of feel- 

 ing, for the said teeth may be felt much more easily than they 

 can be seen. We may thus understand why a razor will cut a 

 hair in two much more easily when drawn against its teeth than 

 in the opposite direction. Dr. Goring. 



