26 THE MICROSCOPE. 



In selecting specimes of traps, limestones, etc., for sectionizing, 

 too much care cannot be used in taking notes of the position, forma- 

 tion and locality from which each specimen is procured. When a 

 specimen loses its " pedigree," it at the same time loses the greater 

 part of its scientific interest and value. — Journal of Postal Micro- 

 scopical Society. 



On Mounting Diatoms, Etc., in Lines and Patterns. — 

 Mr. H. Sharp gives the following directions for this kind of mount- 

 ing, his slides thus prepared being said by Mr. W. H. Wooster to be 

 "exquisite examples of manipulative skill ": 



Requisites. — (i) One or two cat's or mouse's whiskers fastened 

 on match-like sticks or fine rushes, with shellac rather than gum, 

 with about ^ inch free. I prefer to have one with the natural 

 point, and another with the point cut back to where it is somewhat 

 stiffer. (2) A good simple microscope of some kind, either 

 attached . to a roomy stage-plate, with a mirror below and revolv- 

 ing-plate above, or detached on some stand, cut capable of being 

 brought over a mounting-table with mirror and rotating plate as 

 above. My own is home-made, extremely simple, costing nothing 

 but the trouble, and such as any one with a little ingenuity could 

 make for himself. It consists of a piece of pine 9 inches long, 5 

 inches wide, and 1 inch thick, on three legs, with a hole in the 

 centre, into which a wooden match-box (with the bottom cut out) 

 fits tightly, projecting a little above ; over this fits a piece of slate 

 just tight enough to rotate easily ; beneath, a peg receives the 

 mirror of the microscope. This forms the detached mounting- 

 table. For the simple microscope, I take the foot and tube-pillar 

 of the condenser, fit a piece of cane in this tube, drive a pickle- 

 bottle cork stiffly on it, and fasten on this a horizontal wooden bar 

 with a hole in the middle to fit on the cane, and another at each 

 end in which to fit the lenses, which are just the ij^-inch and 

 J^-inch objectives, which give far better definition than common 

 pocket-lenses. (3) A steady hand. (4) Patience and perseverance. 



Dry Mounts. — All diatoms and scales should be mounted on 

 the cover, not the slide. Lay a clean cover on a slide and keep it 

 in place by a drop of water between. As scales are larger than 

 diatoms, it is well to begin with them. Put several on a slide in the 

 ordinary way, pick out the ones wanted with a bristle under the 



