Trouble Adding More Space Between Paragraphs (CSS)

Hi all,
I am trying to add a bit more space between each line in my paragraphs, but it doesn’t seem to be working.

#post-area {
color: #333;
float: left;
font: 17px/19px Cambria, Verdana, Sans-Serif;
overflow: hidden;
position: relative;
width: 610px;
}

I tried adding in the lines below, and was then going to play with the size but these do not change anything:
margin: 10px 0;
line-height: 14pt;

Any help is appreciated. Thanks for looking.