CHAPTEE VI. 

 ON MOUNTING. 



SLIDES. 



Glass slides, 3x1, must be cleaned before using, 

 and a good plan is to keep some cleaned, ready for use, 

 in a two-dozen box with rack work, where they stand 

 on their edges and do not get dusty. The ordinary 

 slides sold at the shops at 6s. a gross, are easily cleaned 

 with a chamois leather. Sometimes, however, especially 

 when using slides for the second time, they cannot be 

 cleaned so readily, and they must be soaked in a decoc- 

 tion of oak galls for some hours ; this is made by pour- 

 ing boiling water on bruised oak galls and straining. 



COVER GLASSES. 



The usual size of these is f of an inch square, but 

 larger ones will be required, and some of | of an inch 

 should be obtained. For practical men square cover 

 glasses are the best ; but where aesthetic mounting is 

 the order of the day, round cover glasses and variously 

 coloured cements for sealing, with the help of a turn- 

 table will be required ; these, for obvious reasons, will 

 not be considered in this work. 



Thin glass is made by Messrs. Chance, of Birming- 

 ham, in three thicknesses, designated by the numbers 

 1, 2, and 3 ; of these No. 1 is the thinnest. This is the 

 best to use. It varies in thickness from '004, or even 

 thinner to -008. 



