Thomas Cargill, physician to the family of Francis Cook's first wife (Emily Lucas), was an important influence on the early development of the garden (1860's). He was also the author of the poem "Fairy Life in Fairyland" that contains so much information about those early times.
The poem makes reference to an area below the "Roman Causeway" and the "Reservoir" that is called Dr. CARGILL'S BED. It is also, on occasion called his "Thalamus" a puzzling designation.
However the following lines concerning the Argan Tree suggest that the principle purpose of the bed was to bring together a collection of scented plants. Indeed the pathway below the reservoir (tanque in Portuguese) was referred to as not only the "Tank walk" but also the "Scented Walk".
The courteous Monarch smiled !
The Queen Invisible Titania led
His steps adown the glowing green
Of our great emerald Lawn to tread
The borders of that great incensed bed,
Far scenting 'Thalamus'
That "great incensed bed" is clear enough, but what of the "Thalamus"? As a widely-read medical man Cargill would have been familiar with cerebal anatomy. Medical treatises from the early nineteenth century onwards were conscient that the sense of smell was transmitted by the olfactory nerve that formed, together with others, the root of an organ known as the "Thalamus" and that the principle function of this organ was the gathering and processing of the senses, not only of smell but of the other four senses as well. Knowledge concerning the function of these nerves had been obtained from the autopsy of patients who had suffered various kinds of sensory loss due to the growth of tumours.
The designation of an area of the garden as a specific place for scented plants is unusual and perhaps unprecedented. However this is symptomatic of the need to order and classify the vast array of new plants available to mid-nineteenth century gardeners; just as plants were grouped according to their geographic origin in other parts of the garden.