REVIEW. 157 



Nature," by Mr. Metcalf Johnson. Dr. Johnson's method 

 of ilhnnination is very simple and ingenious, and appears to 

 be new. A beam of light is sent down the oblique body 

 of the binocular microscope by a plane mirror, a rectangular 

 prism, or the ordinary drawing camera. It falls upon the 

 Wenham prism, and is by this directed through the objective 

 upon the slide, the prism being of course arrangcMl as for 

 binociilar vision. A small portion of the centre of the iield 

 will then, if all the adjustments are correct, be brilliantly 

 illuminated. 



Having thus given, so far as possible, a notion of the 

 actual contents of the first number of ' The Lens,' Ave might 

 almost escape the necessity of pronouncing any formal judg- 

 ment; for it is obvious that the subjects constitute a very 

 rich and varied field of activity, and that the execution has 

 merits of a very high order. If the promise of the first 

 number is borne out by those which follow, we feel confident 

 that ' The Lens ' will take a high and independent position 

 among scientific periodicals. In the name of the oldest of 

 existing journals devoted to microscopical science, we cor- 

 dially welcome this, her youngest sister, who so narrowly 

 escaped perishing among the ruins of Chicago. 



toL. XII.— NEW SEft. 



