COLLECTION OF SPECIMENS 165 



Water, 1 J fluid ounces ; rectified spirit, 1 j ounces ; 

 glycerine, 5 drachms. More often than not, I 

 subject the material for a contemplated mount 

 to both treatments, in order the more effectually 

 to extract the air, the presence of which con- 

 stitutes the principal difficulty in mounting, and 

 the chief factor in the possible future spoiling of 

 the slide. The small china pans in which moist 

 water-colours are sold will he found most useful 

 for the purpose of soaking the specimen in the 

 preparatory fluid; they are made in two sizes. 

 Failing these, watch-glasses form admirable sub- 

 stitutes. Our plant is now ready to be put into 

 the glycerine jelly, and, needless to say, this must 

 be melted before it can be used; hence a hot- 

 water bath becomes a necessity. A very simple 

 and inexpensive one can be made of an ordinary 

 glass tumbler, provided with a closely fitting tin 

 lid having a piece cut out of the margin just 

 large enough to admit the neck of a small glass 

 bottle containing the jelly, but not as wide as the 

 projecting lip of the bottle. When the lid is in 

 place, the bottle (which is from time to time 

 replenished from the larger stock-bottle) can thus 

 hang by its lip in the hot water in the tumbler, 

 and the melted jelly is consequently close at hand 

 for use. If the mounting is likely to take long, 

 it is well to wrap a piece of flannel round the 

 tumbler, in order to retain the heat in the water 

 as long as possible. It should be mentioned in 



