Making invisible ink(隐形墨水) is a lot of fun. All you need is some common materials(材料). |
What you'll need: Half a lemon ·Water ·Spoon ●Bowl ·White paper ●Cotton bud(棉签) ·Light bulb(电灯泡) |
Instructions: ⒈Squeeze(挤) some lemon juice into the bowl and add a few drops of water. ⒉Mix the water and lemon juice with the spoon. ⒊Put the cotton bud into the mixture(混合液) and write a message onto the white paper. ⒋Wait for the juice to dry so it becomes completely invisible. ⒌When you are ready to read your secret message or show it to someone else, heat the paper by holding it close to a light bulb. |
What's happening? Lemon juice turns brown when heated. Putting some water in the lemon juice makes it very hard to notice when you put it on the paper. Other things which work in the same way include orange juice, honey, milk, onion juice and even more. |
