Olfactory feedback for analytical tasks is a virtually unexplored area in spite of the advantages it offers for information recall, feature identification, and location detection. Here we introduce the concept of ‘Information Olfactation’ as the fragrant sibling of information visualization, and discuss how scent can be used to convey data. Building on a review of the human olfactory system and mirroring common visualization practice, we propose olfactory marks, the substrate in which they exist, and their olfactory channels that are available to designers. To exemplify this idea, we present ‘viScent(1.0)’: a six-scent stereo olfactory display capable of conveying olfactory glyphs of varying temperature and direction, as well as a corresponding software system that integrates the display with a traditional visualization display. We also conduct a comprehensive perceptual experiment on Information Olfactation: the use of olfactory marks and channels to convey data. More specifically, following the example from graphical perception studies, we design an experiment that studies the perceptual accuracy of four ``olfactory channels''---scent type, scent intensity, airflow, and temperature---for conveying three different types of data---nominal, ordinal, and quantitative. We also present details of an advanced 24-scent olfactory display: ‘viScent(2.0)’ and its software framework that we designed in order to run this experiment. Our results yield a ranking of olfactory channels for each data type that follows similar principles as rankings for visual channels, such as those derived by Mackinlay, Cleveland & McGill, and Bertin.