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Ibietoloo^ of tbc ^eeth: 

 1RotC6 on flDetho&6 of preparation. 



By V. A. Latham, F.R.M.S. 



HE different methods of hardening, cutting, staining, 

 and mounting which tissues must go through 

 before they are ready for examination seem 

 tedious at first ; but when we understand the 

 reasons^ they are simple enough. As regards 

 re-agents and stains, the fewer and simpler that 

 obtain a given result the better, though when the 

 student is able to use the ordinary stains he can 

 always try others. I do not claim originality in the 

 various methods here given, but have ventured to collect and modify 

 some of the ways given to suit my own work, and to have at hand 

 the principal ones known, or as nearly so as possible. The old 

 method of cutting a fresh tooth into fine sections with a saw, 

 grinding down fine, and thoroughly cleaning, polishing, and 

 mounting in Canada balsam, is one of the best methods for hard 

 sections when not required to show the pulp and more delicate 

 structures. I will not enter into more detail of those methods, as 

 I gave them in T/ie Scientific E^iquirer^ Vol. II., p. 196. 



To Grind Sections of Teeth.— I use ground glass, using with it 

 in the early stage fine-ground pumice-stone, which is especially 

 convenient for grinding rough shells, like those of lobster or crab. 

 By soaking the jaw of a mouse, rat, weasel, etc., in a solution of 

 balsam in benzole, allowing it to become hard, and then grinding 

 down as above, very beautiful sections showing the teeth in situ 

 may be made. 



Structure of Softened Tooth.— 



Vertical Sections of the jaw of cat should be softened in 

 dilute chromic and nitric acid ; mount in Farrant's solution or in 

 glycerine jelly. The latter is preferable. 



Journal of Microscopy and Natural Science. n 



New Series. Vol. II. 1889. 



