Well written book, packed with so many interesting facts about our complementary organs of smell- the nasal and the vomeronasal system- i.e. 'Jacobson's Organ'. The book focuses on the interesting aspects of this vomeronasal system across species- fish, toads, snakes, rats and pigs. It explains how truffles- those expensive mushrooms mimic the pheromones in male pigs- that's why sows are used to sniff out these delicacies. Plants too, seem to send out invisible odours into the air when herbivores begin to feed on their leaves and in this way, neighbouring plants begin producing tannins that make leaves unpleasant to be eaten. The array of facts and experiments on human beings and their sense of smell is quite amazing too. Evidence suggests that smell rather than any other sense is directly connected to the brain, and could explain why smell is deeply linked to memory.
It's also linked to our sense of well-being as well as confidence, which is why we also use perfumes. Although perfumes are supposed to mask our body odours, we use essential oils that are very similar to the structure of our own smells. So we try to mask, but unconsciously, we are bringing to the forefront those very things that we try to hide.
Watson has a lively style, I never did get bored and he has a good take-home message, i.e. not to underestimate the sense of smell, which may be controlling us unconsciously in so many more ways than can be imagined.