162 



Sargon's Palace at Nimroud could never have been intended 

 for use as a lens. As regards typical modern microscopes, we 

 find that practically all the important patterns of quite recent 

 construction have been included ; although to make room for 

 these, many of the descriptions and figures of instruments in 

 the former edition have been omitted. Such gaiety as the book 

 possessed has csrtainly been decreased in this way, for we can 

 no longer turn to it for a quiet chuckle over the delightful 

 pictures of radial and swinging sub-stage microscopes attempting 

 to stand on their heads, wagging their tails, and performing 

 other clever but useless tricks. 



In the chapter devoted to accessory apparatus there are several 

 new features. Nelson's camera lucida, for instance, is fully 

 described, though we fail to find any mention of Ashe's form, 

 which carries out the same idea in a more useful way. New 

 condensers, including Powell and Lealand's apochromatic form 

 with Nelson's correction collar, necessarily receive considerable 

 attention ; and sjDace has also been found for a short account of 

 the rings and brushes shown by certain minerals under polarised 

 light, and for a description of Gifford's F-line screen. 



The section on the preparation and mounting of objects has 

 been very much improved — largely rewritten, in fact — but that on 

 collection remains unaltered. This seems rather a pity, when it 

 is remembered what important advances have been made in the 

 methods of collecting plankton alone. It is curious, too, that 

 no mention is made of the material almost invariably em23loyed 

 nowadays in the construction of nets — namely, silk-gauze. 



The second half of the book, commencing with Chapter VIII., 

 and treating mainly of the minute forms of plant and animal 

 life and other microscopic structures, has not been materially 

 altered, so far as we can see. The main changes are those in 

 connection with the Bacteria, which have been illustrated by two 

 new plates, and the application of the microscope to geological 

 investigation. An appendix has also been added to Chapter XIII. 

 on Rousselet's method of preparing Rotifers. We are not unmind- 

 ful of the very large amount of most valuable information 

 contained in this portion of the book, but we cannot help 

 suspecting that some of the statements would have been some- 

 what modified, and possibly also expanded, if they had been 

 submitted to specialists. This is probably what will have to be 



