262 APPENDIX. 



importance, for in them is the real value of the instru- 

 ment. The stand and its mechanical conveniences are 

 of secondary consequence for the purposes of this work. 

 The different makers combine objectives and eyepieces in 

 various ways. Purchasers are cautioned to see that the 

 magnification is secured by using high-power objectives 

 and low-power eyepieces and ' not by high-power eye- 

 pieces and low-power objectives. 



The accompanying illustrations are included to give 

 those who may need such information an idea of what is 

 necessary for this course. There are very probably other 

 equally good microscopes. If funds are plenty, more 

 expensive stands may be indulged in. 



The Leitz Stand V (see Fig. 189), with objectives 3 

 and 7, eyepieces I and III, giving magnification from 60 

 to 525 diameters, may be imported, duty free, for about 

 $18.50. The Bausch and Lomb Optical Company make 

 a stand of about the same grade and another, their stand 

 AAB (see Fig. 190), which is superior in its mechanical 

 parts ; either of these stands should be equipped with two 

 eyepieces and two objectives, f and l or 1 inch, giving 

 magnifying powers of from 55 to 485 or 770 diameters. 



Directions for the manipulation of the microscope, the 

 preparation of material for temporary examination, the use 

 of the microtome in cutting sections, methods of staining 

 and mounting for permanent preservation, and the pro- 

 cesses used in making photomicrographs, are given in the 

 author's " Practical Methods in Microscopy," 2d edition, 

 published by Messrs. D. C. Heath & Co., Boston. 



4. ACCESSORY APPARATUS. 



A microtome of some sort is a necessity. If one of the 

 more expensive instruments cannot be afforded, a simple 

 hand section cutter should certainly be obtained. The 



