Chloroform and joystick: what they have in common
- Step 1. Chloroform — is used in — General anaesthesia. Chloroform.
- Step 2. General anaesthesia — uses — Chemical reaction. Ether and chloroform are chemical agents.
- Step 3. Chemical reaction — is used in — Percussion cap. Mercury fulminate explodes when struck.
- Step 4. Percussion cap — evolved from — Flintlock. The percussion lock replaced the flintlock.
- Step 5. Flintlock — has part — Spring. A mainspring.
- Step 6. Spring — is part of — Joystick. They return the stick to the centre.