Enfleurage
The oldest known method for capturing plant odours is called enfleurage and it is quite labour intensive. For example, gardenia petals would be soaked in a fat for several days and then the process is repeated until the fat is saturated with the fragrance.
There is a fair amount of misunderstanding with respect to humans using essential oils hundreds of years ago, or for that matter thousands of years ago. During ancient times humans did not have the equipment and technological know-how to extract aromatic hydrocarbons from plants, therefore in order capture the aromatics or perfume aromas was through enfleurage.
Image description: Victorian era photograph depicting several women working in a large hall. Some of the women are sorting through baskets of flower petals, while others are pressing the flowers into wooden trays in preparation for soaking the petals in fat.