By default, in Ubuntu 13.04 Raring Ringtail, the natural scrolling and the horizontal scrolling are disabled, by default. In the previous Ubuntu versions, the horizontal scrolling could be activated via “Mouse and Touchpad” settings, but this feature is not available anymore.
Let’s start: Press Alt + F2 and type dconf-editor
From the left side, choose org –> gnome –> settings-daemon –> peripherals –> touchpad:
In the right window, thick horiz-scroll-enabled and natural-scroll.
