NOT A GOOD PROJECT IF ANY STUDENTS HAVE ASTHMA.

Let's test our sense of smell and the air circulation in the room. We have some perfume in a bottle that has not yet been opened.

Everybody sit very still, so as to not disturb the air in the room. Look at the clock and make a mental note of the exact time. Your teacher will open the perfume bottle, and each student should raise his or her hand when the scent becomes apparent.

A gas is coming from the bottle. We can't see it, but we can smell it. The gas mixes with the air in the room, and travels with the circulation of air. Probably the students closest to the bottle can smell it more strongly than those farthest from it. Note the exact time when the farthest students smell the perfume.

Sometimes, when people have asthma or emphysema, or some other respiratory diseases, the molecules of gas emanating from perfume or flowers (often, many kinds of things that have scent) their breathing passages swell, and they have difficulty breathing. It would be a good idea to ask if anybody in the class has a kind of respiratory disease or is "allergic" to fragrances, before doing this experiment.

Taking turns, let's each tell the rest of the class about some other times we noticed scents when we were not actually trying to smell something. For starters, think about sitting in the living room at home and being able to smell food cooking. Mmmmmmmmmmmmmmmmmm!