CH. I'll] LABELING AND CATALOGING. 173 



\ 295. General Remarks on Catalogs and Labels. — It is especially desirable tbat 

 labels and catalogs shall be written with some imperishable ink. Some form of 

 water- proof carbon ink is the most available and satisfactory. The water-proof 

 India ink, or the engrossing carbon ink of Higgins, answers very w 7 ell. As pur- 

 chased, the last is too thick for ordinary writing and should be diluted with one- 

 third its volume of water and a few drops of strong ammonia added. 



If one has a writing diamond it is a good plan to write a label with it on one end 

 of the slide. It is best to have the paper label also, as it can be more easily read. 



Fig. 136. Writing diamond for writing numbers and labels on glass slides, cul- 

 ling cover-glasses, etc. {Queen & Co.). 



The author has found stiff cards, 12^x7^ cm., like those used for cataloging 

 books in public libraries, the most desirable form of catalog. A specimen that is 

 for any cause discarded has its catalog card destroyed. New cards may then be 

 adde 1 in alphabetical order as the preparations are made. In fact a catalog on 

 cards has all the flexibility and advantages of the slip system of notes (see Wilder 

 &Gage, p. 45). 



Some workers prefer a book catalog. Very excellent book catalogs have been 

 devised by Ailing and by Ward (Jour. Roy. Micr. Soc, 1887, pp. 173, 348 ; Amer. 

 Monthly Micr. Jour., 1890, p. 91 ; Amer. Micr. Soc. Proc, 1887, p. 233). 



The fourth division has been added as there is coming to be a very strong belief, 

 practically amounting to a certainty, that there is a different structural appearance 

 in many if not all of the tissue elements depending upon the age of the animal, 

 upon its condition of rest or fatigue ; and for the cells of the digestive organs, 

 whether the animal is fasting or full fed. Indeed &?> physiological histology is 

 recognized as the only true histology, there will be an effort to determine exact 

 data concerning the animal from which the tissues are derived. (SeeMinot, Proc. 

 Amer. Assoc. Adv. Science, 189^, pp. 271-289 ; Hodge, on nerve cells in rest and 

 fatigue, Jour. Morph., vol. VII. (1892), pp. 95-168 ; Jour. Physiol., vol. XVII., 

 pp. 129-134; Gage, The processes of life revealed by the microscope ; a plea for 

 physiological histology, Proc. Amer. Micr. Soc, vol. XVII. (1895), pp. 3-29 ; Sci- 

 ence, vol. II., Aug. 23, 1895, pp. 209-218). 



CABINET FOR MICROSCOPICAL PREPARATIONS. 



\ 296. While it is desirable that microscopical preparations should be properly 

 labeled and cataloged, it is equally important that they should be protected from 

 injury. During the last few years several forms of cabinets or slide holders have 

 been devised. Some are very cheap and convenient where one has but a few 

 slides. For a laboratory or for a private collection where the slides are numerous 

 the following characters seem to the writer essential : 



(1). The cabinet should allow the slides to lie flat, and exclude dust and light. 



(2). Each slide or pair of slides should be in a separate compartment. At each 

 end of the compartment should be a groove or bevel, so that upon depressing 

 either end of the slide the other may be easily grasped (Fig. 140). It is also desira- 

 ble to have the floor of the compartment grooved so that the slide rests only on 

 two edges, thus preventing soiling the slide opposite the object. 



(3). Each compartment or each space sufficient to contain one slide of the 

 standard size should be numbered, preferably at each end. If the compartments 



