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metal and be so bent as to allow specimens to be 

 brought under them without resistance and keep 

 them properly in place, without too much pressure 

 and consequent friction. 



A Glass Stage and Slide Carrier may be con- 

 sidered a good investment, as it admits of the 

 convenient manipulation of the slide, without the 

 grating feeling which usually accompanies the 

 direct movement of the slide on the stage. 



The Mechanical Stage, while an absolute 

 necessity in petrographical and other work where 

 a systematic search, as for bacilli or in blood count- 

 ing, over the entire surface of object is required, it 

 will also be found a most useful accessory. The 

 obstacle of considerable cost which prevailed until 

 the present time, is now removed and good 

 mechanical stages may be obtained at a very 

 reasonable cost. They are supplied in two forms, 



Fixed mechanical stage, in which the mechanical 

 movement is built on a stage. 



Attachable mechanical stage, which can be at- 

 tached to the Continental stands having plain 

 stage. This has advantages, since it may be re- 

 moved, leaving the stage plate free but, of course, 

 cannot be revolved. Either form involves the 

 most delicate work and while the parts are neces- 

 sarily small should be built with a view to strength 

 and durability. They should work with the 



