(23 Nov 2015, 6:58 pm)S813 FVK wrote Just a thinking point really:
How can you observe a smell? Whenever i have used the term 'observation', it has been looking at things as opposed to smelling.
observe/əbˈzəːv/
verb
1.notice or perceive (something) and register it as being significant.
2.make a remark.
3.fulfil or comply with (a social, legal, ethical, or religious obligation).
I reckon it falls into no1.