16: Secret Writing

weighing balance

de-ionised water 

spray bottles 

potassium hexacyanoferrate(III) solution 

pin board for attaching paper 

copper sulphate solution to be sprayed, 

pins 

ammonium thiocyanate solution 

small paint brushes 

iron(III) nitrate solution 

large sheets of chromatography paper 

ammonia solution 

hairdryer (optional) 

a few drops of phenolphthalein solution 

Bunsen burner or candle in holder 

lemon juice or milk 

eye protection 

cotton buds 

disposable gloves 

phenolphthalein solution