歡迎閱讀《週末科學版》！我們每週五都要為你介紹可以在家中進行的有趣科學實驗。你可以在《科學日誌》中 記錄自己做了哪些活動，這樣就可以將所學的紀錄下來，比較這些結果，也許還可以利用它們來設計新的實驗！先看一下《科學日誌》的點子再開始吧。展開實驗之前，記得要獲得大人許可喔！
Have you ever wanted to write a secret message that only your friends can read? You can do so using a lemon, milk, vinegar or orange juice.
What you will need:
One or more of the following: lemons, milk, orange juice or vinegar
PHOTO: MICHAEL KEARNEY, TAIPEI TIMES
A heat source, such as a 100-watt light bulb
White paper
Cotton swabs
Glasses
Water
▲ Cut one of the lemons and squeeze some of its juice into a cup. Mix in some water.
▲ Put some milk, orange juice and vinegar into separate cups and mix them with water.
▲ Put only water into another cup. This will be your control.
▲ Dip a cotton swab into one of the cups, and use it to write on a piece of paper. Label the piece of paper so you know what kind of “ink” you used to write on it.
▲ Do the same with all your other kinds of “ink.” Use a different cotton swab for each one.
▲ Let the pieces of paper dry until you can’t see your message.
▲ Have a friend hold the piece of paper up to the light bulb. The message should appear. Note that you need to use a hot enough light bulb. Be careful not to burn yourself or the paper. Have an adult help you with this part. Don’t forget to record what happens in your Science Journal.
(MICHAEL KEARNEY, STAFF WRITER)
你曾經想要寫下一個只有你的朋友可以看到的秘密訊息嗎？你只要使用一顆檸檬、牛奶、醋或柳橙汁就可以做到囉。
所需材料︰
一個或多個下列物品：檸檬、牛奶、醋或柳橙汁
一個加熱源，如一百瓦的燈泡
白紙
棉花棒
玻璃杯
水
▲ 切一顆檸檬，把汁擠到一個杯子裡，再加水攪拌。
▲ 分別將牛奶、柳橙汁和醋倒入三個不同的杯子裡，再加水攪拌。
▲ 再拿一個杯子裡面只裝水，這是你的對照組。
▲ 把一根棉花棒放到其中一杯裡蘸濕，然後用它在紙上寫字；在紙上標記你所使用的「墨水」種類，以免混淆。
▲ 使用不同種類的「墨水」重複上述步驟，每次都要換一根棉花棒。
▲ 等紙上的墨水乾到看不見所寫的訊息。
▲ 請一個朋友把紙放到一個燈泡前面，你剛剛寫的訊息應該就會顯現出來。注意！燈泡一定要夠熱才行，另外請小心不要燙到自己或是燒到紙張；請一個大人從旁協助這個步驟。別忘了在《科學日誌》裡記錄下結果。
（翻譯︰袁星塵）
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