_With a propyl preparation ... propyls ... propionic acid._ How did this ever occur to me? On the same evening on which I had written part of the history of the disease before having the dream, my wife opened a bottle of cordial labelled “Ananas,”[W] (which was a present from our friend Otto. For he had a habit of making presents on every possible occasion; I hope he will some day be cured of this by a wife).[X] Such a smell of fusel oil arose from this cordial that I refused to taste it. My wife observed: “We will give this bottle to the servants,” and I, still more prudent, forbade it, with the philanthropic remark: “They mustn’t be poisoned either.” The smell of fusel oil (amyl ...) has now apparently awakened in my memory the whole series, propyl, methyl, &c., which has furnished the propyl preparation of the dream. In this, it is true, I have employed a substitution; I have dreamt of propyl, after smelling amyl, but substitutions of this kind are perhaps permissible, especially in organic chemistry. _Trimethylamin._ I see the chemical formula of this substance in the dream, a fact which probably gives evidence of a great effort on the part of my memory, and, moreover, the formula is printed in heavy type, as if to lay special stress upon something of particular importance, as distinguished from the context. To what does this trimethylamin lead, which has been so forcibly called to my attention? It leads to a conversation with another friend who for years has known all my germinating activities, as I have his. At that time he had just informed me of some of his ideas about sexual chemistry, and had mentioned, among others, that he thought he recognised in trimethylamin one of the products of sexual metabolism. This substance thus leads me to sexuality, to that factor which I credit with the greatest significance for the origin of the nervous affections which I attempt to cure. My patient Irma is a young widow; if I am anxious to excuse the failure of her cure, I suppose I shall best do so by referring to this condition, which her admirers would be glad to change. How remarkably, too, such a dream is fashioned! The other woman, whom I take as my patient in the dream instead of Irma, is also a young widow.