The electrometer gave no sign of electricity. As the storm gathered the blue of the sky changed to grey. The thermometer rose 3'C, as is usual in the Tropics, and a heavy rain fell. Being sufficiently adapted to the climate not to fear the effect of a tropical downpour we stayed on the shore to observe the electrometer. I held it more than twenty minutes in my hand, 6 feet above the ground. For several minutes the electric charge remained the same, and then I noticed that the electricity in the atmosphere was first positive, then nil, then negative. I have gone into these details on the electric charge in the atmosphere because newly arrived European travelers usually describe just their impressions of a tropical storm. In a country where the year is divided into two halves, the dry and the wet season, or as the Indians say in their expressive language, 'of sun and rain', it is interesting to follow meteorological phenomena as one season turns into the next.

The passage from the mouth of the Río Negro to Grand Para took only twenty to twenty-five days, so we could have gone down the Amazon as far as the Brazilian coast just as easily as returning by the Casiquiare to Caracas. We were told at San Carlos that political circumstances made it difficult to cross from Spanish to Portuguese colonies, but we did not know until our return to Europe what danger we would have been exposed to had we gone as far as Barcellos. It was known in Brazil, probably through newspapers, whose indiscretion is not helpful for travelers, that I was going to visit the Río Negro missions and examine the natural canal uniting the two river systems. In these deserted jungles the only instruments ever seen had been carried by the boundary commissioners. The Portuguese Government agents could not conceive how a sensible man could exhaust himself 'measuring lands that did not belong to him'. Orders had been issued to arrest me, seize my instruments, and especially my astronomical observations, so dangerous to the safety of the State. We were to be led along the Amazon to Grand Para, and then back to Lisbon. Fortunately, the Lisbon Government instantly ordered that I should not be disturbed but rather encouraged.

If the independent Indians have almost disappeared over the last century in those areas north of the Orinoco, it must not be concluded that fewer Indians exist at present than in the time of the bishop of Chiapas, Bartolomeo de las Casas. I have already proved in my work on Mexico how mistaken it is to assume the destruction and diminution of Indians in the Spanish colonies, as Ulloa has written 'Es cosa constante irse disminuyendo por todas partes el numero de los Indios' (There is everywhere a constant decrease in the number of Indians). There are still more than 6 million copper-colored races in both Americas, and though countless tribes and languages have died out it is beyond discussion that within the Tropics, where civilization arrived with Columbus, the number of Indians has considerably increased. (61)

We entered into the cave following the rivulet, some 28 to 30 feet wide. We walked along the banks as far as the calcareous incrustations allowed us; frequently, when the current slipped between high clusters of stalactites, we were forced to walk along the river bed, only 2 feet deep. To our surprise we learned that this underground stream is the source to the Caripe river and becomes navigable for canoes a few leagues from here, after joining the Santa Maria river. Along the underground rivulet banks we found a quantity of palm-tree wood, remains of trunks used by Indians to climb to the cave's ceiling when searching for nests. The rings formed from the traces of the leaf stems are used as a perpendicular ladder.