384 APPENDIX 



ber of large shot to weight the wax, otherwise, as it 

 separates from the sides of the dish in cooling, it wiU 

 iloat when water is poured into the dish. If tin dishes 

 be used, smear some of the melted wax over the inside 

 of each to prevent rusting. The dishes should be washed 

 and thoroughly dried after being used. 



14. Dissecting-Needles. 



These are invaluable in the examination of small organ- 

 isms, pieces of tissue, etc. They may easily be made by 

 thrusting the eye end of sewing-needles into pen-holders 

 made of soft wood. It is well to have several pairs 

 made with needles of different sizes. 



15. D issec ting- Trays. 



Convenient trays may be made of deal boards measur- 

 ing eighteen by twelve inches. They may have a narrow 

 moulding or a deep groove at the edge to catch the 

 fluids and prevent them from soiling the tables. The 

 trays should be thoroughly oiled before being used, as 

 the oil prevents the wood from absorbing fluids and fa- 

 cilitates cleaning. If desired, the trays may be stained 

 black with a solution of logwood before being oiled. They 

 should be thoroughly cleansed each time after using. 



16. Eosin. 



Use. — Stain for alcoholic or fresh tissues. 



Preparation. — Prepare the alcoholic solution by dissolving 

 one gram of eosin in ninety-nine cubic centimetres of 

 ninety-flve per cent, alcohol. When using, add this solu- 

 tion to alcohol in the proportion of one drop of the 

 former to twenty drops of the latter. The aqueous solu- 

 tion is prepared by dissolving in distilled water sufficient 

 eosin to produce the depth of color desired. 



17. Glycerine . 



Use. — Clears tissues ; serves as a temporary mounting 

 medium. 



