There are also claims that all essential oils contribute to the formation of phagocytes, ie, white blood cells that greedily eat invasive bacteria. In a German book on the Pharmaceutical Application of Essential Oils, published in 1906, Rudolf Cobert notes that they stimulate the formation of anti-toxins, which he considers to be one of their most important functions. The ability of essential oils to affect the immune system is also a topic discussed by Roveti, who states that such an effect occurs regardless of whether the oils are administered by massage, inhalation, or by mouth. He cited a compatriot of his own, Benedictine, who “provides for the preparation of preparations based on bergamot, lavender and lemon essences capable of stimulating curative leukocytosis (increase in the number of white blood cells) in various types of infections.” Other essential oils are quoted as a stimulant of leukocytosis. In 1964, in a study by X.M.Gatfossa (son of the author who introduced the term aromatherapy), it is proven that all essential oils enhance phagocytosis but to varying degrees (phagocytosis is the ability of the white blood cell and to swallow germ-infected microbes).