A novel method has been discovered for the preparation and application of a special vapourized mixture having therapeutical characteristics. This method has now been used for curing specific diseases in plant, human and animal cells by fully subjecting such affected cells to such vapourized mixture. This mixture is generated from a heated liquid, such as water, in which controllably a certain quantity of certain free gas particles e.g. hydrogen and oxygen is added, whereafter a chemical reaction takes place and a new material composition, specified as "Aquatilis", is created under simultaneous generation of heat. These free hydrogen and free oxigen gas particles with which the vapour mixture is enriched thereafter are kept in a state wherein diseased cell structures, are entirely and intensively surrounded by the "Aquatilis" mixture, and whereby during the treatment said mixture is kept in an enclosed space, e.g. a saunacabin (1). The mixture is kept at a predetermined elevated temperature by generating more free gas particles and maintaining in said space a predetermined vapour pressure, thereby forcing "Aquatilis" to attack e.g. chemical groups of socalled radicals which are considered to be found in certain diseased cell structures, thereby essentially and agressively supporting and augmenting the inner cellular offensive system energy against the presence of any noxious nuclei which affect the normal operational cell functions and destroying thereby such noxious nuclei entirely. The mixture has been successfully used to cure a.o. major diseases such as incurable multiple sclerosis, skin cancers and is believed to cure also patients from aids diseases.