MOUNTING OF MICROSCOPIC OBJECTS. 



the alcohol, as originally placed, not having needed any of these 

 complicated manipulations), immediately replacing the cover to 

 exclude dust. 



It will be observed that I rigorously exclude turpentine in all 

 forms from my work. I have ever found it a most unsatisfatory 

 medium, foul smelling, sticky, and rendering all tissues immersed in 

 it stiff and brittle. Oil of cloves, on the contrary, is in all respects 

 a most admirable medium, rendering all tissues and substances fully 

 as clear as turpentine; is agreeable to, the sense of smell, does not 

 stiffen anything immersed in it, and is perfectly miscible with bal- 

 sam or damar. 



After this digression, and whilst our specimens are clearing up 

 in the oil, let us see to our glass slips and covers, and to the balsam 

 in which the former are to be mounted. Very many processes for 

 cleaning the slips and covers have been given to the world by vari- 

 ous writers, and probably they are all good. I give only my own, 

 which I have used for many years, with entire satisfaction, and 

 therefore can confidently recommend it. The slips (which should b e 

 smooth edged), are placed in a basin with hot water and good soap, 

 and wiped dry with a soft towel, after being thoroughly 

 washed and rinsed. They are then placed in a drawer, 

 and are ready for use at any future time, merely requiring to be 

 brushed off with the large camel's hair pencil when used. The thin 

 covers (which should always be circles, and not squares, as making 

 neater and more readily finished mounts), are dropped one by one 

 in a glass tumbler, containing sulphuric acid, 

 and allowed to remain there for some hours. 

 The acid is then poured off, and water carefully 

 added, which in its turn is decanted and re- 

 placed with fresh water, the whole contents of 

 the glass being freely agitated until every 

 trace of the acid is removed. One of the glass 

 pomatum jars is now to be partially filled with 

 alcohol, and the thin covers placed therein to 

 remain until wanted for use, when they can be 

 Fig. 6. Mounting removed with the forceps, and a slight wiping 

 table with lamp. ^.^ ^ ^ soft Hnen handkerchief will leave 



them brilliantly clean. 



My own preference is for absolutely pure filtered balsam as af- 



