The impulse of which this study of olfaction is the outcome emanated from Sir St. Clair Thomson, who three years ago handed me for my edification and growth in knowledge the _Essai d’Olfactique Physiologique_, a _Thèse de Bruxelles_, by _A. Heyninx_, dated 1919. In addition to that work the following have been utilised, for the scientific side of the subject at all events:— _Poncelet, P. P._ Chimie du Goût et de l’Odorat, etc. Paris. 1755. _Parker, G. H._ Smell, Taste, and Allied Senses in the Vertebrates. n.d. _Deite, C._ Manual of Toilet Soap-Making. Eng. Trans., 2nd ed. London. 1921. _Ogle, Wm._ Medico-Chir. Trans., Vol. LIII., p. 263. _Bonvier, E. L._ The Psychic Life of Insects. Eng. Trans. London. 1922. In Heyninx’s book there is a good bibliography, but the English reader will find an excellent _résumé_ of recent scientific literature in _Osmics_, by Mr. J. H. Kenneth, published by Oliver & Boyd, Edinburgh. It is impossible in the space at my disposal to print a bibliography dealing with the historical aspect of olfaction. In addition to my debt to books, I am also under deep obligation to Dr. Wyatt Wingrave, Dr. Arnold Renshaw, Mr. Archer Ryland, Mr. F. W. Watkyn-Thomas, and Mr. T. H. Fairbrother, for many valuable hints and criticisms, as well as for much useful information, and I take this opportunity of offering my thanks to them for their kind interest. INDEX Acetone poisoning, Odour of, 84 Adsorption of odours, 113 Æneid, The, Odour in, 72 Albinos, Anosmia of, 116, 126 Alcoholism, Odour of, 84 Alexander the Great, 77 Ambergris, 106 Ammonia, 94 Animals, Lower, Olfaction in, 21 Aniseed, 71 Anosmia, 23, 115, 142 Anti-demoniac treatment by fumigation, 67 Ants, Olfaction in, 28 Apoplectick, Balsam of Horstius, 69 Aromatics, The, 119 Asthma from horses, 93 Asafœtida, 71 Aura, Olfactory, 91 Bacon, Francis, 84 Badger, Olfaction in, 37 Bat and sound-pictures, 32 Bath, The domestic, 18 Baudelaire, 51 Bay, 73 Bazin, Réné, 144 Bean-flowers, Fragrance of, 145 Beltane fires, 143 Bolboceros beetle, 37 Books, Smell of, 146 Brain, Olfactory Routes in, Unknown, 136 Brewer, Anthony, 53 Browning, Robert, 71 Burton, Robert, 78 Cairo, Cholera in, 68 Camphor as disinfectant, 70 Carminatives, 71 Castelli’s theory of vision, 127 Cats, Aversion towards, 92 Cities and towns, Smells of, 150 Civet, 106 Collins, Wilkie, 47 Colosseum, Perfumes in the, 56 Coumarin, 105 Creighton, 84 Crowd-psychology and Odour, 97 Death, Odour of, 84 Deite, 104, 117 Devil, Odour of the, 63, 73 Dickens, Charles, 54, 148 Disease, Epidemic, and Stenches, 5, 66 Odours of, 83 Disraeli, Benj., 12 Dog, The, and the Abominable, 80 Olfaction in the, 34, 87 truffle-hunter, the, 34 Dostoievsky, 56 Dwelling-houses, Odours of, 148 Eau de Cologne, 57 Einstein and the ether, 138