Traversing London between sunset and sunrise to chart the scents of the city at night, Bompas & Parr collected London's aromas as perfumes that were then shipped to photographer Thomas Brown who photographed them with stylist Lyndsay Milne.

This olfactory mapping exposes how smells represent an invisible architecture, shaping and enhancing our experience of the city's urban environment. Certain odours act as sensory landmarks, hard wired into our brains, orientating life.

Another view having a certain number of advocates is, that cholera depends on an unknown something in the atmosphere which becomes localised, and has its effects increased by the gases given off from decomposing animal and vegetable matters. This hypothesis is however, rendered impossible by the motion of the atmosphere and, even in the absence of wind, by the laws which govern the diffusion of aeriform bodies.

—John Snow, On the mode of communication of cholera, 1855. p.114