“ The essential oil forms a convenient medium for using cloves for flavouring purposes, it possesses the medicinal properties characteristic of a volatile oil, and it is frequently employed to relieve toothache. Oil of cloves is regarded by many dental surgeons as the most effective local anaesthetic they possess in cases where it is desired, before cutting a sensitive tooth for the purpose of filling it, to lower the sensibility of the dentine. ”

“ The chief commercial sources of supply are now Zanzibar and its neighbouring island Pemba on the East African coast, and Amboyna. Cloves are also grown in Java, Sumatra, Réunion, Guiana and the West India Islands.
Cloves as they come into the market have a deep brown colour, a powerfully fragrant odour, and a taste too hot and acrid to be pleasant. When pressed with the nail they exude a volatile oil with which they are charged to the unusual proportion of about 18%. The oil is obtained as a commercial product by submitting the cloves with water to repeated distillation. ”