286 PRACTICAL MICROSCOPY. 



moderate-sized volume may be written, as it applies to all 

 objects whether mounted dry, in gum resins, or in aqueous 

 media, and may be simply described as an operation for 

 eliminating matter in the wrong place dirt. Foreign 

 matters should be eliminated as much as possible, and 

 really when set about in the right way it is not very difficult. 

 When we come to compare the slides of diatoms put up by 

 Cole, Redfern, or Redmayne with many home-mounted 

 slides it may be readily seen what is the effect of a little 

 care on the part of the preparer. Cole's exceedingly clean 

 gatherings, his hand-picked slides, Redfern's single diatom, 

 mounted on a J-inch cover in the centre of a red circle -^ of 

 an inch in diameter, and Redmayne's diatom slides all 

 deserve imitation. 



Let us turn again to the mounting of mosses : how many 

 of the ol TroXXot are content with placing the specimen in 

 glycerine jelly, dirty as when collected, making no effort 

 at all to divest it of its useless and degrading accompani- 

 ment ! 



It is to be hoped that these few words will act as an 

 incentive to cleanly working ; all the requisites are several 

 camel's-hair or sable pencils, one of which should be cut 

 short so that the hair projects but a quarter of an inch 

 beyond the quill-holder. The knives, scissors, forceps, 

 needles and other articles have been already described in 

 the chapter on dissections ; it may, however, be necessary to 

 state that each article should be kept for its specific uses, as 

 if knives, scissors, and needles be used for mounting pur- 

 poses they will soon be out of order for dissections. 



Most objects can be cleansed under water with the 

 brushes and needles in the small dissecting troughs shown 

 in Fig. 152; these can be used under a watchmaker's eye- 

 glass or on the stage of the microscope under a half-inch, 

 with erector such as has been already described. 



