6 MICRO-ANALYTICAL METHODS 



meats, etc., as it often gives' a due to the quality of the sub- 

 stances and to the means of getting quick results. 



4. Equipment for Micro-analytical Work 



The equipment and apparatus required by the micro-analyst 

 is comparatively inexpensive, and it is very earnestly advised to 

 secure only those appliances which are useful or essential for the 

 work in hand. The following list is submitted without entering 

 into detail, as it may be assumed that the microscopist does not 

 require explanations: 



1. Simple lens. 



2. Compound microscope. 



a. Ocular with micrometer scale. 

 J. Oculars, Nos. 2 and 4. 



c. Objectives, Nos. 3, 5 and 7. 



d. 1/12 in. oil-immersion objective for bacteriological work. 



3. Slides and covers. 



4. Section knife or razor, and strop. 



5. Polarizer, for the study of starches, crystals and other substances. Should 

 be convenient to use. The selenite plates are useful. 



6. Thoma-Zeiss hemacytometer; for counting bacteria and yeast cells. 



7. Stage mold and spore counter, as descrilied in Part. II (Fig. 5). 



8. Accurate metal or hard rubber millimeter ruler for measuring seeds (in fruit 

 products), etc. 



9. The required glassware and adjunct apparatus. 



10. The required reagents. 



11. Equipment for making moisture determinations. 



12. Equipment for making ash determinations. 



13. Equipment for the required bacteriological tests and determinations. 



The laboratory in which the work is done should be roomy, well- 

 lighted, provided with the necessary shelves, apparatus and supply 

 cases, reference books, etc. The details need not be given here. 

 The analyst must see to it that the necessary things are provided. 

 A skillful and experienced worker should have the tools of his 

 choice, not those selected for him by some one not qualified to 

 judge. 



The skilled micro-analyst has little difliculty in determining 



