2 CLINICAL BACTERIOLOGY AND H^MATOLOGY 



cases it is useless to think of having an inefficient fine adjust- 

 ment altered for bacteriological use. 



There are now many microscopes which are sold at a com- 

 paratively small price, and which will answer every purpose. 

 It is hardly necessary to specify these, as the practitioner can 

 obtain all the information he requires from the catalogues of 

 such firms as Swift, Baker, Watson, etc., all of whom make 

 instruments that can be recommended. 



With regard to eye-pieces, it is an advantage to have two, a 

 No. 2 and a No. 4. High powers may be used, but it must 

 be remembered that any increased gain in magnification 



FIG. i. HOT-AIR STERILIZER : SIMPLE FORM. 



brought about by the eye-piece is attended by a loss of defini- 

 tion. The same applies to the increased magnification obtained 

 by pulling out the draw-tube. 



The total cost of a microscope may be put down at 15 (now 

 considerably increased), and for this sum a thoroughly efficient 

 instrument can be obtained, while one that will answer every 

 purpose may be bought for decidedly less. The cost of 

 adapting a good staiid will be about 6 IDS. or 7 (305. or 2 

 for the substage arrangement and 5 for the lens), or less if a 

 cheaper oil-immersion lens is obtained. 



A mechanical stage is a very great advantage in hsemato- 

 logical work, since it enables a preparation to be moved 



