COLLECTIONS. 



117 



THE MAKING OF COLLECTIONS. 



A good, representative collection of diseased material is a prime necessity in 

 every pathological laboratory. This grows into completeness only with the lapse 

 of much time and the aid of many hands. It should include photographs, drawings, 

 paintings, dried material, representative specimens preserved in strong alcohol, and 

 serial sections properly stained and mounted in Canada balsam or Dammar balsam, 

 which must not be dissolved in chloroform, since this gradually removes the stain. 

 With the accumulation of much material, some sort of classification becomes im- 

 perative. At present the writer keeps 

 the material designed for sections in 

 95 per cent alcohol, arranged in as 

 many groups as there are parasites 

 involved. Each jar of material finally 

 receives the same number as the 

 paraffin block from which sections 

 are cut. This material must be exam- 

 ined at least once a year to see that 

 the alcohol has not evaporated, es- 

 pecially if corks are used. Only the 

 best velvet corks should be pur- 

 chased, and as an additional precau- 

 tion they should be sealed in with 

 paraffin. The negatives are filed away 

 in similar groups, protected by nega- 

 tive bags. The stained sections, 

 mounted in balsam, are filed away 

 in cheap wooden boxes (Pillsbury 

 boxes), each holding 25 slides (figs. 

 103, 104). These are very conven- 

 ient, if properly made, but some 

 boxes of this sort lead to much vexa- 

 tion of spirit, the grooves being too 

 narrow to receive any but the thin- 



Fig. 104.* 



nest slides. Those sold in recent years by Bausch & L,omb have given no trouble. 

 In the form shown in fig. 104 the cover remains on better and the mounted slides 

 are easier to take out, but in drying the preparations with the cover off, these boxes 

 tip over at the least touch. During this drying, which requires from a few days to 

 several weeks, the slides should, of course, lie flat, not on edge. 



*Fic. 104. Another style of slide-box. The advantages of this box are that the cover is not 

 likely to fall off and that the slides, in case of full boxes, are withdrawn more easily. The disad- 

 vantages are that it is tipped over very easily when standing on end open, that the cover is readily 

 mistaken for the bottom when it is closed, and that if the cover is put on upside down the writing 

 on the edges is divided. These may also be had from Bausch & Lomb. 



