The chemical senses are considered to be taste and smell. Taste and smell are so important to everyday living. I know from experience that when I get the common cold my sense of smell and taste seem to “disappear”. Humans do not need to have the sense of smell to survive, whereas animals do in fact need that sense. When humans try and detect smells, they tend go with the stronger scent. When someone has a cold, though, their senses become weak and they cannot pick up on the stronger scent. Humans can recognize scents, but they can never label them accurately. This appears to be caused by an inability to retrieve the name from memory, not from a lack of sensitivity.
Perception plays a big role in smell. When someone smells and scent their perception takes over. They automatically remember a time or perceive that smell to be a certain object. The picture below shows a bundle of lemons. When I smell lemons, I think about summertime, lemonade, even my job at Rita’s Water Ice.