166 MOSSES AND LIVERWORTS 



passing that, whatever pattern of hot-water bath 

 is adopted, it is advisable to put the jelly in actual 

 use into quite a small bottle, as this avoids the 

 evaporation of the water contained in it, which 

 would result if the same jelly were frequently 

 melted. The glass slip to receive the specimen, 

 as also the cover-glass by which it is to be pro- 

 tected, must be thoroughly cleaned before being 

 used; a good plan is, first to rub them over 

 between the finger and thumb with a little acetic 

 acid, in order to remove all grease, and then to 

 well wash them in clean water (hot water is better 

 than cold), drying them with a soft cambric 

 handkerchief, and finally polishing with a wash- 

 leather. The drying of the cover-glasses is at 

 first a matter of some difficulty, owing to their 

 extreme thinness; but with a little practice the 

 process soon becomes a perfectly easy one, though 

 greater care has to be taken with the square 

 glasses, as the corners are apt to catch in the 

 handkerchief. The slip and glasses should be tilted 

 against something until ready for use, and care 

 must be taken to use the lower faces in mounting, 

 as dust is not so likely to have settled there in 

 the meantime as on the upper sides. 



The plant to be mounted is now taken out of 

 the preparatory fluid, and is placed on a glass slip 

 in a little of the fluid, both in order to keep it 

 moist, and to avoid the risk of air making its way 

 in again ; it is then subjected to further examina- 



