Can I Toggle content of Element based on pixel height of element?

Can I Toggle content of Element based on pixel height of element?

Using Bootstrap 2.3.2 I've previously used a toggle button to show and
hide text using the Collapse plugin but from what I see it only allows me
to reveal and hide the entire contents of an element.
What I need is to already have 170px of the element's content visible and
then when the button is clicked, it reveals the rest of the text in the
element - but I need to do this without adding any additional elements, it
needs to be based on height.
Is this possible with Bootstrap? Or if not, jQuery?