SECTION THREE 



Phosphates 



Solution required: 



Ammonium molybdate io% in 

 concentrated nitric acid. 



Technique: 



Place sections on a slide in a drop of the reagent, and examine 

 under the microscope. 



Results: 



Phosphates are indicated by small black-bordered yellow drops, 

 which develop into spaerocrystals and afterwards into cubes and 

 octahedrons. 



Phjrtosterol 



Solution required: 

 Gram's iodine. 



Technique: 



1. Place thick sections on slides and cover with concentrated 

 sulphuric acid. 



2. If phytosterol is present sections will assume a red color- 

 ation. Add a drop of Gram's iodine solution and mix by rocking 

 the slide backwards and forwards gently. 



Results: 



The presence of phytosterol is confirmed when the colour 

 changes from red, after the addition of the iodine, to violet ; then 

 blue and finally to yellowish red or brown. 



Potassinm 



Solution required: 



Sodium Cobalt Nitrite. 



Sodium nitrite . . . . • • 7 gn^« 



Cobalt nitrate . . . . • • 4 g"^- 



Distilled water . . . . . . 13 ml. 



Glacial acetic acid . . . . 2 ml. 



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