eg stands for the Latin phrase exempli gratia, meaning “for example.”
Based on the little bit of code you gave here, the code provided above will work. however if you have other styling saying differently, then it
may take precedence...e.g.
p {clear:both}
we won't know unless we can see more of your CSS sheet and the area around what you are trying to affect.
The only other thing I can think of is your reader doesn't follow the styling that is included with the ePub...it uses it's own built-in styling. What reader are you testing on, and does it have a "use publisher styling" option, or somesuch?