Scrolling with a Magic Mouse
Apple’s Magic Mouse uses many of the same gestures as the trackpad, and you can customise them. To change the direction pages scroll when you swipe up and down with one finger, open the Mouse pane in System Preferences, click on Point & Click. Uncheck ‘Scroll Direction: Natural’.
You can switch off the secondary ≈- click on the right-hand side of the mouse here, if you find the lack of a separate external button confusing. We find, though, that if you leave it on, you get used to it.