52 Dr Goring on Monochromatic Light, <§r. 



incuria, qua etiam dudurn periere, multo illorum damno, alia, 

 sed domestica animalia, sues, anseres, Sec. 11 



This is an apposite remark, the interest of which is height- 

 ened by the analogy made use of concerning the extinct rein- 

 deer of Iceland. 



. Unfortunately, however, for the confirmation of these re- 

 mote historical allusions, we have not, I believe, upon record 

 the account of any fossil animals of the Rangifer having yet 

 been discovered among the wilds of Caithness or Sutherland. 

 But as the extinct zoology of Britain has been hitherto imper- 

 fectly studied, the objection is far from being a formidable one. 

 Until lately, countless bones of fossil animals have been de- 

 stroyed, under the impression that they were the unfit objects 

 of any museum whatever. 



Leigh, in his Natural History of Lancashire, (Book 3d, 

 p. 84,) has stated, that the horn of a rein-deer was found under 

 a Roman altar discovered at Chester, and he has given a draw- 

 ing of it. But the delineation is that of a fragment only, and 

 its character is too indeterminate. Leigh, however, was a good 

 naturalist, considering the time in which he lived, and we are 

 scarcely warranted in roundly asserting that he was deceived. 



Art. VI. — On Monochromatic Light, and on the Achroma- 

 tism and Spherical Aberration of Eye-pieces and Engy- 

 scopes. By Charles Goring, M, D. Communicated by 

 the Author. 



a he scheme of illuminating microscopes by monochromatic 

 or homogeneous light, in order to render their chromatic aber- 

 ration insensible, appears in theory extremely plausible ; ne- 

 vertheless, there are many objections to it. In the first place, 

 it is evident that all sorts of monochromatic illumination what- 

 soever must be far less intense than the ordinary kinds, in as 

 much as they must consist of one of the seven constituent pris- 

 matic colours abstracted from the rest ; for if a beam of light 

 is divided into seven parts, and only one of them is taken, 

 (though it should be the brightest of the set,) it must follow 

 that it will be far fainter than the combination of the whole. 



