Olfactory Bulbs and Memories (republished)
Perhaps that is why a smell has such a powerful effect on our emotions. A certain smell can cause an inadvertant physical reaction (the smell of rotting meat for instance) and just adding a smell to a descriptive passage of prose adds immediate power. Yet it is easy to overdo and I often feel that there are not enough words for 'smell' - just perfume or odour.
Our ability to detect smell is quite extraordinary. It takes just one molecule to set off a signal, and just a slight change in the shape - just the mirror image of the molecule - can initiate an entirely different sensation. This makes the construction of artifical noses quite difficult. This was something I was involved in trying to produce during my post-doctoral work. The artificial nose has to be able to detect very low concentrations of gases and also be uniquely selective. In the project I was working on we used a sensitive electrical balance. My function as a chemist was to design coating that would adsorb (absorb just on the surface) the required molecule. The plan then was to construct an array of miniscule balances so that each smell would generate a fingerprint. It was very interesting work and sometimes I wish I was still doing it.
On the Athanasius Kircher site there is a feature about smells preserved from East Germany. That is something few of us ever think of doing - and yet the memory of a smell can sometimes transport us into our pasts more effectively than any other sense.
(This post has been repubished with 'comments allowed'. Comments seemed to be disabled before - I have no idea why becuse when I checked my settings - which I hadn't touched since my last post - they seemed to be still allowed. Ah well, they seem to be back now. Another little mystery, I guess).