In this masterful lecture on the alchemical sublimatio, one of the major operations of the alchemical opus, Dr. Edinger explores images and meanings related to the process by which the material is turned into air by volatilizing or elevating it. All images that refer to upward movements, such as ladders, climbing or flying, pertain to the symbolism of the alchemical sublimatio. Edinger clearly unfolds the complex symbol system centered around this operation and illustrates with dreams and texts the clinical relevance of alchemy to the practice of depth psychology, also stressing the dangers of the alchemical sublimatio in our times.