waffles and pancakes

I have been remiss in posting, despite having learned many useful things in the last few months. Here is one:

When making waffles or pancakes, you do much better to separate the whites from the yolks of the eggs and beat the whites separately till they are stiff (or close). Make the batter with the yolks and then fold the beaten egg whites into the batter. Fluffy, light waffles!

One thing I am interested in is whether you could replace all rising agents with this technique. After all, how did they make pancakes before there was easily available double-acting baking powder?