APPENDIX 



paraffin into the pan until it stands J inch deep over the 

 bottom. When it cools the wire will hold it in, and speci- 

 mens may be pinned to it at will. 



FIG. 2. Dissecting Instruments. 



REAGENTS. A few reagents are necessary in preserving 

 the specimens and for other purposes. Alcohol, 95 % and 

 85 %, and formalin, 4 %, are necessary for preserving speci- 

 mens. 80 % and 85 % alcohol may be made from the 

 95 % alcohol by dilution with water. A normal salt solution 

 (a | % solution of salt in water) is useful in mounting speci- 

 mens that might be destroyed by the osmotic power of 

 water. Glycerin, for mounting objects temporarily; Canada 

 balsam, for mounting hard objects ; and 20 % nitric acid, for 

 preparing tissues to dissect the nervous system, are also de- 

 sirable. Methyl green is useful in staining fresh or preserved 

 tissues. Dissolve it in water, using about as much powder 

 as the water will dissolve, and add a few drops of acetic acid. 



