30'i SUMMARY OP CURRENT RESEARCHES RELATING TO 



WiCKSTEED, E. J. — The Microscope ,- its history, construction, utility and 

 improvement. 



[Title only of communication to the Ottawa Microscopical Society.] 



8cience,_ III. (1884) p. v. 

 Weight, L. — Microscopic Test-Objects — Aperture and Kesolution. 

 [Criticism of " Monachus " and E. M. Nelson."] 



Engl. Mech., XXXVIII. (1884) pp. 470-1 (2 figs.). 

 „ „ Microscopic Tests. 

 [Reply to " Monachus " and E. M. Nelson.] 



Ungl. Mech., XXXIX. (1884) p. 34. 

 Zentmayer's Nose-piece. [_Supra, p. 285.] 



Amer. Hon. Micr. Joum., V. (1884) pp. 42-3 (1 fig.). 



0. Collecting, Mounting and Examining Objects, &o. 



Preparing and Mounting Sections of Teeth and Bone.* — 

 J. E. Ady explains as follows what he terms the " laccie " method of 

 occlusion. 



1st. Saw a piece off the tooth or bone, rub it flat on an engineer's 

 file, polish the flat surface on a fine hone, Water-of-Ajr stone being 

 preferable. 



2nd. Fasten the section on to a piece of plate-glass, 1 in. square, 

 with a cement made by melting six parts of " button " lac with one 

 part Venice turpentine. 



3rd. File the section down moderately thin, and then reduce 

 further on the Water-of-Ayr stone, examining from time to time with 

 the Microscope. 



4th. Soak the section off with strong methylated spirit, wash 

 thoroughly in clean spirit, and dry between tissue paper. 



5th. Make a thin solution of white shellac in methylated spirit, 

 filter, and keep in a stoppered bottle. 



The section is to be dipped in this solution, drained, and laid on 

 a cold plate under a bell-glass. In about half an hour it will be 

 dry. 



6th. Mount in cold balsam and benzol in preference, in order 

 to avoid heating the section, as that would give it a tendency to curl ; 

 but as the melting point of the shellac is higher than that of the 

 balsam, the latter may be used if thought desirable, as it may even be 

 caused to boil without affecting the shellac. 



Expanding the Blow-fly's Tongue.t— C. M. Vorce writes : — 

 If the head of a living fly be cut off, the tongue will usually 

 retract ; pressure on the head will expand the tongue, but unless it 

 be secured by some means before the pressure on the head is released, 

 it is apt to wholly or partly retract again. If only the tip is wanted, 

 it is easily secured by placing the severed head on a clean slip and 

 pressing it with a needle till the tongue is fully expanded, when a 

 drop of turpentine is applied, a cover laid on the tongue, and a clip 

 applied before the pressure is removed from the tongue. To secure 

 the whole tongue, split one end of a small stick for an inch or so, 



* Journ. Quek. Micr. Club, i. (1884) p. 332. 

 t Amer. Mon. Micr. Journ., v. (1884) p. 12. 



