77 MOUNTING AND LABELING. 



5. When the object appears translucent the clearer is drained off and 

 blotted from the edge of the specimen (§ 175). 



6. A drop of the resinous medium is put directly on the object or 

 spread upon a cover-glass. 



7. The cover-glass is put upon the object and pressed down. It may 

 then be heated gently. 



8. The slide is labeled (§ 179). 



9. The preparation is cataloged and safely stored (§§ 181-183). 



10. After the resin has hardened round the edge of the cover the su- 

 perfluous material may be cleaned away and the cover-glass sealed with 

 shellac. This is not absolutely necessary, but is desirable (§ 169 C). 



LABELING, CATALOGING AND STORING MICROSCOPICAL PREPARA- 

 TIONS. 



\ 17S Every person possessing a microscopical preparation is interested in its 

 proper management ; but it is especially to the teacher and the investigator that 

 the labeling, cataloging and storing of microscopical preparations are of im- 

 portance. "To the investigator, his specimens are the most precious of his pos- 

 sessions, for they contain the facts which he tries to interpret, and they remain 

 the same while his knowledge, and hence his power of interpretation, increase. 

 They thus form the basis of further or more correct knowledge ; but in order to 

 be safe-gnides for the student, teacher, or investigator, it seems to the writer that 

 every preparation should possess two things ; viz., a label and a catalog or his- 

 tory. This catalog should indicate all that is known of a specimen at the time 

 of its preparation, and all of the processes by which it is treated. It is only by 

 the possession of such a complete knowledge of the entire history of a prepara- 

 tion that one is able to judge with certainty of the comparative excellence of 

 methods, and thus to discard or improve those which are defective. The teacher, 

 as well as the investigator, should have this information in an accessible form, so 

 that not only he but his students can obtain at any time all necessary information 

 concerning the preparations which serve him as illustrations and them as ex- 

 amples." 



\ 179. Labeling Ordinary Microscopical Preparations. — The label ($ igr ) should 

 possess at least the following information : — 



EXAMPLE. 



(1) The number of the preparation. i No. 475. 



(2) The thickness of the cover-glass. Cover-Glass, .15 mm. 



(3) The name and source of the prepara- 



tion. 



(4) The date on which the preparation 



is made. 



Striated Muscular Fibers, Sartorius of 

 Cat. 



October 1, 1S91. 



