• It filters all that air and retaining particles as small as a pollen grain with 100% efficiency.

• It acts as a humidifier, adding moisture to the air you breathe, preventing dryness of the lining of the lungs and bronchial tubes.

• It warms cold air to body temperature before it arrives in your lungs.

• moths can smell a single molecule of the moth pheromone bombykol

• taste is 75% smell
• all smells are small molecules (less than 350 molecular mass)
• everyone has a unique smell (except identical twins)
• compulsive nose picking is called rhinotillexomania

Human beings have a very weak sense of smell, and it doesn't always work well. When we have a cold, excess mucous blocks the receptor cells, and we have trouble smelling. When we smell the same odour for too long, the receptor cells get 'tired', and stop sending signals to the brain, so we stop smelling the persistent odour.
So, if all of a sudden you find your candle doesn't smell as good as the one you bought last month, try changing your fragrance for a while...

One thing from the above list thats worth pondering over, "Everyone has a unique sense of smell", its often puzzled me, that a fragrance I really love someone else dislikes. Take Clean Cotton for example, this is one of my personal favourites, however, friends of ours thinks it smells like French toilet disinfectent? Obivously I couldnt just shug my shoulders and not question further. A lot of it is down to association, apparantly whatever they use ni France to clean toilets with has, at least in our friends mind, a similar smell to Clean Cotton by Yankee Candles. Maybe they do use Clean Cotton in France, who knows ?!