A good test for cassia oil substituted for oil of cinnamon is to add nitric acid, specific gravity 1.36, to oil of cinnamon (one part of the latter to two parts of acid), and shake the mixture. A bright orange-colored liquid is first obtained, upon the surface of which floats an orange, resinous substance, slowly becoming deeper in color, until a beautiful cherry-red color is visible, by which time it has changed to a liquid that floats on a lighter-colored substratum, which also in a short time becomes nearly of the same tint. Bubbles then commence to appear and shortly afterwards spontaneous ebullition occurs, with the evolution of nitrous fumes and vapors of benzoic aldehyde. By the time this ebullition has ceased the amber-colored liquid commences to clear itself and finally a clear amber liquid is left with orange globules floating on its surface. Upon oil of cassia, nitric acid, specific gravity 1.36, has a different action, as, after mixing one part of oil of cassia with two of nitric acid, a dirty green supernatant resinous mass (slowly turning brown) is seen floating on a yellowish liquid, and no further change takes place. If a large excess of the acid be added after the first addition, the resinous mass changes to a deep reddish brown and the subnascent liquid takes a cherry-red color. The same reaction occurs if a large excess of nitric acid be added to oil of cassia at first, but in neither of these cases is there any spontaneous ebullition or evolution of the nitrous fumes and benzoic aldehyde vapors. If oil of cassia be mixed with oil of cinnamon, the reaction with nitric acid takes place as with oil of cinnamon, but more tardily, according to the amount of cassia oil present; and, at the end of the process, a turbid subnascent liquid is seen, instead of a clear one, as is the case with pure oil of cinnamon. Spirits of nitrous ether can also be used to distinguish between these oils, as it forms a clear solution with that of cinnamon, but a turbid one with cassia. CHEMICAL COMPOSITION OF CASSIA AND CINNAMON Samples examined, ash of the whole being about 8 per cent. and powdered 5 per cent.: Ash Saigon, 8.23 Unknown Cassia, 1.75, extreme Fiber Saigon, 26.29 Fiber of Cassia 14 to 20, extreme Cinnamon, Fiber True Cinnamon, 33.08 Albuminoids Saigon, 4.55 Albuminoids Unknown 2.45, extreme Cassia, Lime True Cinnamon, 40.09, 36.98, 40.39, in three specimens Lime Cassia Lignea, 25.29 Lime “Cassia Vera,” 52.72 Magnesia, True 2.65, 3.30, 3.86, in three specimens Cinnamon, Magnesia, Cassia 5.48 Lignea, Magnesia, “Cassia 1.10 Vera,” ------------------------------------------------------------------------ [Illustration: CLOVES (Eugenia Caryophyllata of Caryophyllus Aromaticus) 1 Zanzibar 2 Amboina 3 Penang 4 Bencoolen 5 Calyx 6 Calyx 7 Flowering stem with leaves]