Point = part of figure.

Oh yes! = letter or piece of paper.

Most certainly = coin, other than money.

Yes, if you like = a watch.

This is harder = some trinket.

I am afraid this is harder = a ring.

An excellent idea = a playing card.

As an example of how this code can be employed, it may be imagined that the Professor lays his hand casually upon a gentleman’s coat-sleeve.

Prof.—What am I touching?

Mlle.—A part of some one’s clothing.