“The second thing to remember is that a REAL WITCH is always bald."
      "Bald?" I said.
      "Bald as a boiled egg," my grandmother said.
      I was shocked. There was something indecent about a bald woman. "Why are they bald, Grandmamma?"
      "Don't ask me why," she snapped. "But you can take it from me that not a single hair grows on a witch's head."
      "How horrid!"
      "Disgusting," my grandmother said.
      "If she's bald, she'll be easy to spot," I said.  “said.
      "Not at all," my grandmother said. "A REAL WITCH always wears a wig to hide her baldness. She wears a first-class wig. And it is almost impossible to tell a really first-class wig from ordinary hair unless you give it a pull to see if it comes off. “Then that's what I'll have to do," I said.
      "Don't be foolish," my grandmother said. "You can't go round pulling at the hair of every lady you meet, even if she is wearing gloves. just you try it and see what happens."
      "So that doesn't help much either," I said.
      "None of these things is any good on its own," my grandmother said. "It's only when you put them all together that they begin to make a little sense. Mind you," my grandmother went on, "these wigs do cause a rather serious problem for witches.” “witches."
      "What problem, Grandmamma?"
      "They make the scalp itch most terribly," she said. "You see, when an actress wears a wig, or if you or I were to wear a wig, we would be putting it on over our own hair, but a witch has to put it straight on to her naked scalp. And the underneath of a wig is always very rough and scratchy. It sets up a frightful itch on the bald skin. It causes nasty sores on the head. Wig-rash, the witches call it. And it doesn't half itch.”

Chapter 2: “How to Recognise a Witch