They were dancing the renowned "Can-can." A handsome girl in the set before me tripped forward lightly to meet the opposite gentleman, tripped back again, grasped her dresses vigorously on both sides with her hands, raised them pretty high, danced an extraordinary jig that had more activity and exposure about it than any jig I ever saw before, and then, drawing her clothes still higher, she advanced gaily to the center and launched a vicious kick full at her vis-a-vis that must infallibly have removed his nose if he had been seven feet high.

It was a mercy he was only six.
That is the can-can.

The idea of it is to dance as wildly, as noisily, as furiously as you can; expose yourself as much as possible if you are a woman; and kick as high as you can, no matter which sex you belong to.
There is no word of exaggeration in this.

Any of the staid, respectable, aged people who were there that night can testify to the truth of that statement.

There were a good many such people present.