ABSTRACT
On the passport the Spanish government issued him before he set off for America in June 1799, Alexander von Humboldt had asked that the name of the botanist who accompanied him – ‘mon ami (secrétaire) A. Goujau-Bonpland' – be written down, as well as a special mention of the equipment he was taking on board, referring to the extraordinary array of portable ‘instruments de physique et d'astronomie' he had assembled – barometers, thermometers, hygrometers, electrometers, compasses, dipping needles, magnetic needles, microscopes, timekeepers, etc. 1 In themselves, those few words sounded like the announcement of a programme: completing the catalogue of nature through the discovery of new botanical species, on the one hand, and understanding the face of nature through the observation of plant geography and the making of multiple measurements, on the other. Both were to be part and parcel of the scientific travellers' endeavour (Figure 5.1 ).
