At present we shall be chiefly interested in the seringueira (Siphonia elastica).

The collection of the latex from the seringueira and the subsequent process of coagulation were simple enough. A seringueiro, or rubber-collector, started from his hut early every morning carrying with him a small steel axe or pick, the head of which was 3 in. long and shaped like a bird's beak; a tin bucket, and some barro—soft clay which had been soaked in water. He walked along the estrada or track which he had cleared for himself, leading from one rubber tree to the next. There may be twenty, thirty, fifty or more rubber trees that have been tapped on one estrada, according to the district and the activity of the seringueiro. In the case of a new tree a collar of the fibre of burity palm was in the first instance nailed with pegs of hard wood round the stem, not horizontally, but at an angle: sometimes, when necessary, in a spiral. In other cases a similar band of clay was made to encircle the tree. These collars served as channels, compelling the latex, as it exuded from cuts made in the tree, to flow into a small tin cup suspended at the lowest point of the collar. The incisions were never made lower than 2 or 3 ft. from the ground. They must not penetrate deeper than the entire thickness of the bark of the tree, and they must on no account touch or wound the actual wood, or the tree would suffer greatly—even die. In some regions the incisions were made longitudinally, in others transversely. The operation was repeated by the seringueiro each time on every rubber tree as he went along the estrada, the latex flowing freely enough into the tin cup after each fresh incision had been made.

The seringueiro thus tapped each tree on his way out along the estrada, which in some cases may be several miles long; in other cases, where rubber trees were plentiful, only a few hundred yards in length. On his return journey the seringueiro emptied each small tin cup—by that time filled with latex—into the large bucket which invariably accompanied him on his daily round. Rubber-trees possess in a way at least one characteristic of cows. The more milk or latex one judiciously extracts from them, the more they give, up to a certain point. But, indeed, such a thing is known as exhausting a tree in a short time. A good seringueiro usually gives the trees a rest from the time they are in bloom until the fruit is mature. In some regions even a much longer respite is given to the trees—generally during the entire rainy season. In some localities, too, in order to let the latex flow more freely, a vertical incision is made above and meeting a horizontal one. At intervals oblique incisions are cut next to the vertical ones, but in Matto Grosso I never saw that complicated system of incisions adopted—only vertical incisions parallel to one another at a distance of 0·25 m. (9⅞ in.) being made there, and in rows one above another. Some of the trees had actually hundreds of those cuts—many, of course, healed. Each cut only exudes latex for a comparatively short time, merely an hour or so.

During the first month after a tree is tapped, the supply of latex is generally plentiful; the second month it gives less; less still the third month. On an average twenty trees give about one litre of latex a day. Three litres of latex are necessary in order to obtain one litre of rubber. At the head-waters of the Arinos River 600 trees gave from 30 to 35 arobas (450 to 525 kils.) of fine rubber in the first month, and about 20 arobas (300 kils.) of sarnambé (second quality with impurities). One aroba is 15 kils.

The latex of the seringueira in the Arinos region was of a beautiful white, quite liquid, and with a pungent, almost sickening, odour. When a new tree was tapped, the lower towards the ground the incisions were made the better. If after considerable tapping the tree did not yield much, it was advisable to incise the tree higher up. In that region the trees exuded latex more abundantly when they began to have new leaves in October. Late in the dry season the latex flowed less freely. When the weather was windy all the latex seemed to contract to the summit of the trees and hardly flowed at all from the incisions. When it rained, on the contrary, it flowed freely, but was spoilt by being mixed with water; so that a good seringueiro must know well not only where and how, but also when to tap the trees, in order to get good results.

Balls of Rubber outside a Seringueiro's Hut.

Method of Pressing Rubber into Cakes.

The alum process of coagulation being used.

Several ways were employed in order to coagulate the latex. The simplest was the one used in Matto Grosso. The latex was poured into a rectangular wooden mould, 0·61 m. long (2 ft.), 0·46 m. wide (1½ ft.), and 0·15 m. deep (about 6 in.). Upon the latex was placed a solution of alum and warm water. Then coagulation took place. In order to compress the coagulating latex into solid cakes, a primitive lever arrangement was used—merely a heavy wooden bar, one end of which was inserted into the cavity of a tree, above the wooden mould, while at the other end of the bar heavy logs of wood were suspended. One night was sufficient for the latex to coagulate thoroughly and be properly compressed into cakes, weighing each about 22½ kils. The cakes were lifted out by belts of liane which had been previously laid into the moulds.

The discoverer of the method of coagulating rubber with alum was Henry S. Strauss. He also found that by keeping the latex in hermetically sealed vessels it could be preserved in a liquid state. The same result could be obtained with ammonia.

In the Amazon and Para Provinces a different process was used. The latex was coagulated by placing it near the fire. The heat evaporated the aqueous part and coagulated the vegetable albumen. In order to make what was called a garrafa, or large ball of rubber—some weighed 20, 30, 40 kils. and more—a small ball of latex was made to coagulate round a horizontal bar of wood. That ball was gradually increased in circumference by smearing it over with more latex, which became gradually coagulated and dried by the heat and smoke produced by the burning of certain woods, and of the oily seeds of the urucuri palm, technically known as the Attalea excelsa. In this process the rubber did not remain white, as with the alum process; in fact, it became dark brown, almost black, owing, of course, to the smoke. Locally, the smoking process was said to be the better of the two, for the coagulation with alum took away somewhat from the elasticity of the rubber.

Interesting was the sorveira (Collophora utilis), a tree which gave latex that was quite delicious to drink, but could not be coagulated. The trees, to any untrained person, closely resembled the seringueira, only the leaves were more minute and differently shaped. It must be remembered that nearly all the trees of the Brazilian forest had leaves only at a very great height above the ground, and it was not always easy to see their shape, especially when close to other trees where the foliage got interwoven into an almost solid mass. We frequently enjoyed the sweet milk of the sorveira—it tasted slightly of fresh walnuts with sugar on them. It was unsafe to drink too much of it, as it had injurious effects upon one's digestive organs.

There was there also the leiteiro (or producer of milk), a smaller tree, and the liana macaco, which both produced abundant milk, but in neither case had a way, so far, been found to coagulate it.

The two days spent at Porto Velho were interesting. The four men who had remained with me behaved fairly well, principally owing to the prospect, that, in drifting down stream, they would not have to work, and would be saved the heavy trouble of grooming, packing and unpacking the animals, and the tedious job every morning of riding miles through the country in order to recover those that had strayed away during the night.

"Thank heaven!" exclaimed Antonio, as he gazed at the canoe, "we shall not have to hunt for her every morning!"

"Yes," answered Filippe, "no more pack-saddles to fix, no more leading the animals to drink. She"—pointing to the canoe—"can drink all the time if she likes...."

Filippe was a prophet. The canoe did "drink" all the time, much to our concern. Little did my men suspect before we started that they would have the hardest time of their lives—so hard, indeed, that it was amazing humans could endure it at all.

One of the three seringueiros at Porto Velho interested me greatly. He was a tall, gentlemanly, refined person, who seldom uttered a word. I noticed that he avoided meeting me, and, although extremely civil, seemed afraid to enter into conversation. The little shed he had built himself (7 ft. by 4 ft., and 7 ft. high) was extraordinarily neat, and open on all sides—quite unlike the sheds Brazilian rubber collectors build themselves.

From my tent I watched him. The man got up before sunrise every day, going at once to the river for a swim. Humming some sort of a song, he would then go through a series of gymnastic exercises, interrupted by sonorous slaps upon different parts of his anatomy to kill impertinent mosquitoes, of which there were swarms on the Arinos River. That done, he would assume a suit of working-clothes, and, returning to his shed, would pick up his tools and noiselessly depart, so as not to disturb our sleep! At sunset, when he returned, he immediately proceeded to the river to have another swim and to get rid of the many insects which always collected upon one's person in going through the forest. Then he put on a clean suit of clothes, and, saluting us from a distance, went to his shed to rest.

I was certain the man was not a Brazilian, but as curiosity is not one of my chief characteristics I took no special notice of him. This brought him round to my tent one evening. The man was a German by birth, of a good family and excellent education. He could speak German, English, French, Spanish and Portuguese to perfection, and was well versed in the literature of those languages. He had evidently drifted about for many years in many parts of South America in search of a fortune, in the Argentine, in Uruguay, and had ended by becoming a slave in Brazil. Yes, the poor old man was a voluntary slave. He had borrowed from his employer and was unable to repay. He was therefore a slave in the true sense of the word, as his employer could, according to local custom, sell him to any one he chose.

The Arinos River above the Rapids.

I was terribly upset to see a European in such a position, and, what was worse, I was not in a position to help. Nor indeed was help asked for or wanted. The old fellow bore the burden bravely, and said he had never been happier in his life. Supposing he were made to return to his own country—from which he had been absent so many years—he philosophically argued, what could he be, with no money and no friends, but a most unhappy man? All his relatives and friends must have died; the habits he had acquired in the wilds were not suitable for European cities; he was too old to change them. The German was an extraordinarily fine type of a man, honest, straightforward, brave. He spoke in the kindest and fairest way of his master. He had sold himself because of necessity. It was now a matter of honour, and he would remain a slave until it was possible to repay the purchase money—some four hundred pounds sterling, if I remember rightly—which he never expected to be able to repay at all.

The German told me some interesting things about the immediate neighbourhood of the camp. The Indians of the Cayapo tribe, who lived close by, did not interfere with the seringueiros. He had been there several years in succession, and he had never seen an Indian. The seringueiros only went to collect rubber during some three or four months each year, after which time they returned to the distant towns south as far as Cuyabá and Corumbá. At the beginning of the rainy season, when the time came for them to retire, the Indians generally began to remind the seringueiros that it was time to go, by placing obstacles on the estrada, by removing cups or even the collars from the rubber trees. But so far in that region, although footmarks of Indians and other signs of them had been noticed, not one individual had been actually seen. Their voices were frequently heard in the distance singing war songs.

"Hark!" said the German to me, "do you hear them?"

I listened attentively. Far, far down the river a faint chorus of voices could just be heard—intermittent sounds of "huá ... huá ... huá ... huá." In the stillness of the night the sound could be distinguished clearly. It went on until sunrise, when it gradually died out.

There was a big lagoon to the west of Porto Velho, formed by the river at high water. The lagoon dried up during the dry season. It was separated from the river only by a narrow tongue of land, 80 ft. high.

I took careful and repeated observations for latitude, longitude, and altitude, the latter by a boiling-point thermometer, from our point of departure at the headwaters of the Arinos River. The elevation of the river was there 1,200 ft. by aneroid, 1,271 ft. by the hypsometrical apparatus. The latitude was 14° 2′·2 South; the longitude 56° 17′ West of Greenwich.

We were having beautiful, clear skies. Only on July 4th at sunset a solitary streak of mist extended to the summit of the sky.

I had two plans in my mind when I decided to descend the Arinos River. One was to abandon that river at the point where it met the Juruena River and strike across country westward until the Madeira-Mamore Railway was met. The other plan—even more difficult—was to continue down the river as far as its junction with the Tres Barras, from which place I would strike across the virgin forest as far as the Madeira River. I had not the faintest idea how I could realize either plan with the ridiculously meagre resources at my disposal. I had money enough, but unfortunately that was one of the few spots on earth where money was of little use. Again I trusted in Providence to come to our help. Both plans involved thousands of kilometres of navigation of a diabolical river, in an almost uncontrollable canoe, with an insufficient and absolutely incapable crew. Then would come the crossing of the virgin forest on foot, for some hundreds of kilometres—nobody knew how many. The least number of men necessary in order to be able to carry provisions sufficient to execute either plan was thirty. I only had four. Yet I started. The second plan was successfully carried out, but necessarily at the cost almost of all our lives, and with sufferings unimaginable.