34 REVIEWS. 



by a disc of bluish-black neutral tint glass placed obliquely in front of the 

 chimney. Parallel to this disc, and behind the chimney, is placed a 

 metallic reflector, which concentrates the light. 



For the engravings which illustrate the above remarks, from the 

 work of Dr. Sckacht, to which we have already referred, we are indebted 

 to the liberality of its publisher. 



We would gladly have loitered over the microscope and its appur- 

 tenances, but we are reminded that our space has been nearly occupied, 

 while those who have devoted, we might almost say, the energies of their 

 life to its study and use are waiting an introduction to any of our readers 

 with whom they have not had a previous acquaintance, and with each of 

 whom we will only say a few words, trusting that those to whom they are 

 addressed will cultivate a closer personal acquaintance. 



We have already expressed our sense of the importance of the " Treatise 

 on the Use of the Microscope," by Mr. Qtiekett, which is deservedly entitled 

 a practical treatise, as in it nearly every difficulty which the practical ob- 

 server meets with has been ably and lucidly treated. To give extracts 

 from such a work would be almost impossible, as any isolated fragments 

 would convey a most unjust, because inadequate, idea of its merits ; we 

 may, however, glance at its general arrangement, so as to show those of 

 our readers who may not be possessed of it (and we should say they are 

 few) how rich its treasures are. Mr. Quekett divides his treatise into 

 three divisions, or parts, which treat severally of Mechanical Arrangement, 

 The Use of the Microscope, and Manipulation. To the first of these we 

 have already referred in our glance at the history of the microscope, 

 with which the work opens, affording, in its introductory chapter, a 

 valuable sketch of its chequered career, which interested us not the less 

 because some of our own earlier observations were made with such rude 

 instruments as are figured and described in it. This chapter is followed by 

 an account of the simple and compound microscopes, and the accessory 

 instruments used with them. In the present edition (the second) a 

 seeming omission made in the first has been corrected, by a description 

 being added of all the best instruments made by our Continental neigh- 

 bours. We were glad to see this addition, as, while it does full justice to 

 the ability and skill displayed by such makers as Plossel and Schiek, of 

 Vienna ; Pistor, of Berlin ; and names still better known to the English 

 microscopist Oberhauser and Nachet, of Paris, it also shows the manifest 

 superiority of instruments made by Smith and Beck, Ross, and others 

 whose names are as familiar to us as household words. This part con- 

 cludes with a chapter " On the Magnifying Powers used with Simple and 



