The beautiful Guanaguana valley stretches towards the east, opening into the Punzera and Terecen plains. We would have liked to visit those plains to explore the petroleum springs that lie between the Guarapiche and Areo rivers, but the rainy season had started, and every day we had problems trying to dry and preserve our plant collections Near Punzera we saw little bags woven in silk hanging from the lower branches of the savannah trees. It is the seda silvestre, or wild silk of the country, which has a lovely sheen but is rough to the touch. The moth that weaves these cocoons is perhaps the same as the one in the Guanajuato and Antioquia provinces that also makes a wild silk. In the beautiful Punzera forests grow two trees that are called curucay and canela; the first because it yields a resin much sought after by the piaches, or Indian sorcerers; the second because its leaves smell like proper cinnamon from Ceylon.

The natural sciences are connected by the same ties that link all natural phenomena together. The classification of species, which we should consider as fundamental to botany, and whose study has been facilitated by introducing natural methods, is to plant geography what descriptive mineralogy is to the rocks that form the outer crust of the earth. To understand the laws observed in the rocks, and to determine the age of successive formations and identify them from the most distant regions, a geologist should know the simple fossils that make up the mass of mountains. The same goes for the natural history that deals with how plants are related to each other, and with the soil and air. The advancement of plant geography depends greatly on descriptive botany; it would hinder the advancement of the sciences to postulate general ideas by neglecting particular facts.

Two main aims guided my travels, published as the Relation historique. I wanted to make known the countries I visited, and to collect those facts that helped elucidate the new science vaguely named the Natural History of the World, Theory of the Earth or Physical Geography. Of these two aims, the second seemed the more important. I was passionately keen on botany and certain aspects of zoology, and flattered myself that our researches might add some new species to those already known. However, rather than discovering new, isolated facts I preferred linking already known ones together. The discovery of a new genus seemed to me far less interesting than an observation on the geographical relations of plants, or the migration of social plants, and the heights that different plants reach on the peaks of the cordilleras.

April 30th. We continued upstream on the Atabapo for 5 miles, then instead of following this river to its source, where it is called the Atacavi, we entered the Temi river. Before reaching this tributary, near the Guasacavi mouth, a granite outcrop on the west bank fixed our attention: it is called the rock of the Guahiba Indian woman, or the Mother Rock, the Piedra de la Madre. Father Zea could not the explain its bizarre name, but a few weeks later another missionary told us a story that stirred up painful feelings. If, in these deserted places, man leaves hardly any traces behind him, it is doubly humiliating for a European to see in the name of a rock a memory of the moral degradation of whites that contrasts the virtue of a wild Indian with the barbarity of civilized men!

Such considerations have guided my researches, and were always present in my mind as I prepared for the journey. When I began to read the many travel books, which form such an interesting branch of modern literature, I regretted that previous learned travelers seldom possessed a wide enough knowledge to avail themselves of what they saw. It seemed to me that what had been obtained had not kept up with the immense progress of several sciences in the late eighteenth century, especially geology, the history and modifications of the atmosphere, and the physiology of plants and animals. Despite new and accurate instruments I was disappointed, and most scientists would agree with me, that while the number of precise instruments multiplied we were still ignorant of the height of so many mountains and plains; of the periodical oscillations of the aerial oceans; the limit of perpetual snow under the polar caps and on the borders of the torrid zones; the variable intensity of magnetic forces; and many equally important phenomena.

If you compare the Río Negro with the Amazon, the River Plate or the Orinoco it is but a river of the second order. Possessing it has been, for centuries, of great political interest for the Spanish Government because it affords its rivals, the Portuguese, easy access into the Guianan missions to worry the Capitanía-General of Caracas in its southern limits. Three hundred years have passed in pointless territorial disputes. In different times, according to their degree of civilization, people have leaned either on papal authority or on astronomy. As they have generally been keener to prolong this dispute rather than solve it, only nautical science and geography have gained anything. When the affairs of Paraguay and the possession of the Sacramento colony became important for the two Courts of Madrid and Lisbon, commissioners were sent out to study the boundaries of the Orinoco, Amazon and River Plate. Besides the idle, who filled archives with their complaints and lawsuits, there were a few educated engineers and some naval officers acquainted with the means of determining the position of a place. The little we knew up to the of the last century about the geography of the interior of the Continent is due to these hard-working men. It is pleasing to remind ourselves that the sciences gained accidentally from these border commissions, often forgotten by the states that sent them out.

Under such favorable circumstances, and crossing regions long unknown to most European nations, including Spain itself, Bonpland and I collected a considerable number of materials, which when published may throw light on the history of nations, and on our knowledge about nature. Our research developed in so many unpredictable directions that we could not include everything in the form of a travel journal, and have therefore placed our observations in a series of separate works.