Cinnamomum zeylancium is derived from the bark, leaves and twigs of the tree.  It has a potent, sweet, spicy aroma.  Cinnamon oil is classified as a middle note and is extracted via steam distillation.  The bark oil is much more expensive as the yield is much lower than the leaves.  It has a wide range of therapeutic uses due to its stimulating, carminative and antiviral properties.  It blends well with warm citrus aromas such as sweet orange and lemon.  Due to the presence of cinnamic aldehyde, cinnamon may cause allergic reactions if you are hypersensitive to this ingredient.  Avoid using when pregnant or lactating.  As it is a high irritant to mucous membranes it is not recommended for use in the bath, in steam inhalations or in concentrations > 0.5%.  Instead try incorporating this oil in a foot bath, massage oil, room spray or in your own diffuser blend.