CLEANING, LABELING, AND STORING SLIDES 77 



type of cabinet shown in Fig. 57. There are arguments for and against both 

 methods of storage. SHdes which are stored vertically occupy much less space 

 than do those which are stored flat. The former method is not very suitable 

 for wholemounts for the reason that the interior of the slide never dries and, 

 after a slide has been stored for some years in a vertical position, the object 

 will be found to have dropped down to the edge of the coverslip and become 

 embedded in the hardened balsam, from which it is very difficult to detach it 

 later. There is, however, no objection to the storage of sections on edge, and 

 many thousands of slides stored by this method can be kept in the space which 

 is occupied by only a few hundred when they are stored flat. 



Another method of storing slides, which is particularly useful in the case of 

 serial sections involving many dozens of slides in each series, is to take two 

 3- by 5-in. index cards and to cut about an inch from the long edge of one of 

 them. They are stapled together, making a series of pockets into each of which 

 a slide may be inserted. The full data connected with the slide may be written 

 on the card, which may be stored in any of the ordinary card-filing cabinets 

 that are available. 



There are many types of small boxes made which have grooves to hold the 

 slides. It is to be remembered with these that the slide must be kept in a hor- 

 izontal position if it is a wholemount. 



There is a considerable case to be made out for "ringing" the edges of cover- 

 slips with a colored varnish not only to improve the appearance of the slide 

 but also to increase its permanence. This procedure is described in full in 

 Gray's Microtechnique, and space does not permit it to be given in the present text. 



