154 THE MICROSCOPE. Oct. 



amine cut off a sprig- about one half of an inch long-, place 

 on a g-lass slip in a drop of water, cover and then see that the 

 cover is completely filled with water. An inch objective 

 is all that will usnally be required. It frequently requires 

 sharp eyes to observe the under leaves which frequently 

 aid in the determination of species. 



An Improvised Erector. — For dissecting- or manipulat- 

 ing- under the microscope it is necessary to erect the im- 

 ag-e, at least, in order to work with comfort or precision. 

 A cheap erector may be quickly improvised by fitting a 

 right ang-led prison over the eye piece with the, widest face 

 from the observer. 



Logwood Staining. — To bring- out details of structure 

 and display cell walls, etc., there is no better stain than log-- 

 wood, and for sing-ly stained veg-etable sections it is to be 

 recommended in preference to all other staining- fluids. A 

 log-wood violet fluid is prepared as follows: 



1. 'Haematoxylin 20 g-rains 



Absolute Alcohol 1-2 ounce 



2. Solution of 2 g-rains of alum to one ounce of 

 water. 



To stain proceed as follows: 



First: — Remove the sections from alcohol to water for a 

 few minutes. 



Second: — To alum solution for ton minutes. 



Third:— Stain in No. 1. . 



Fourth: — Place in alum water to remove stain from sur- 

 face. 



Fifth : — Wash thoroughly in water. 



Sixth: — Place in alcohol for two or more hours. Float 

 the section lig-htly on the surface of oil of cloves — when it 

 sinks it is ready to be mounted in balsam. 



A Comparison of Lenses. — A novice recently purchased 

 a lens from an itinerant ag-ent of a foreig-n manufacturer. 

 With the lens he also purchased a slide of Pleurosig-ma an- 

 g-ulatum. Upon the g-rand re=^olutioii of this slide the 

 novice based his opinion of his new lens. 



Full of faith and confidence he carried his lens and slide 



