188 THE MICROSCOPE. 



hol, then soak in turpentine and mount in balsam immediately. 



When mounting in balsam use a 7-8 circle or a rectangular 

 cover. Be sure that the space to be covered is well filled with 

 the mounting medium; too much is better than too little. It 

 will frequently be necessary to hold the cover down until the 

 balsam sets. Hold down in the center with a rubber tipped 

 pencil, press out ail air bubbles and' take care that the balsam 

 fills the space beneath the cover. 



The leaves are of a beautiful refreshing green and the calyp- 

 tra? or fruit capsules and the teeth of the peristome are instruc- 

 tive and beautiful objects. 



As opaque objects they may be mounted in the same way by 

 adding a dark back ground. A collection of mosses will furn- 

 ish enough material to keep one busy all winter. Before mount- 

 ing, read up Bryophyta in Bessy's Botany, Mosses in an Ency- 

 clopedia, in Carpenter on the Microscope, or consult some spe- 

 cial work. In this way, a mastery of the subject can be attained 

 together with a proper judgment as to what is to be seen and 

 mounted. Carpenter recommends mounting them on wooden 

 slides. 



The Circulation of the Blood. — In a tumbler of Algse, I 

 noticed three or four objects about a quarter of an inch in size, 

 moving vigorously about. Placing one in a shallow cell, filled 

 with water and covered, I examined with an inch objective. I 

 think it was some sort of aquatic larva. But what attracted my 

 attention and filled me with delight was the beautiful display 

 of the general circulation of the blood. On viewing with the 

 quarter inch objective the Elipticd Corpuscles were plainly and 

 beautifully visible, the action of the heart was revealed and the 

 circulation observed in every part of the body. 



How to Spread Blood for Examination. — Select for a 

 spreader a plain glass slip with a smooth and true edge. Place 

 the drop of blood on a slide to the left of the center. Press the 

 spreader tightly on the slide and draw it firmty to the right. 

 For immediate examination place a thin cover over the center. 

 The capillary attraction and the adhesive qualities of the blood 

 will cement it quite securely. It can then be examined even 

 with an immersion lens if care be taken to let none of the fluid 

 run under the cover. For a permanent mount omit the cover, 



