344: ELEMENTS OF COMPARATIVE ZOOLOGY. 



in water before dissection, as otherwise the acid will attack 

 the dissecting instruments. 



Fuehsin is one of the most easily used stains. It is made 

 by dissolving one part of the aniline dye in two hundred 

 parts of water. 



Picrosulphuric Acid is used for killing many animals with- 

 out distortion. It is made by dissolving picric acid in water 

 until no more will be taken up, and then adding to one 

 hundred parts of the solution two parts of sulphuric acid. 

 It is allowed to stand a day, is filtered, and is prepared for 

 use by adding three parts of water to one of the stock solu- 

 tion. Specimens killed in this fluid are stained yellow, 

 and should be washed in several changes of water before 

 being placed in alcohol or formol. It takes from one to 

 three hours to kill. 



