SULFUR from POPOCATEPETL* NORMAN J. HARRAR Franklin College. Franklin, Indiana
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INCE ancient times it has seemed perfectly natural to associate the element sulfur with smoking volcanoes. The largest accumulations of the yellow "'burning stone" have been found in volcanic regions of the earth, although in some cases it is difficult to trace a connection between the brimstone beds and the nearby fiery furnaces. The fact is that in the most important producing areas, those of Sicily and the American Gulf Coast, the sulfur happens to occur in sedimentary structures. Deposits of sulfur resulting directly from volcanic activity have rarely been of much commercial significance. For centuries the "Gold of Sicily" dominated the world markets and in recent years the immense resources of the Gulf Coast have made this region preeminent. Volcanic craters have been and still are exploited in Japan and Chile, but the production has always been relatively small. In many respects, however, one of the most interesting sulfur mines in all the world lies within the crater of a famous volcano in old Mexico. SMOKE MOUNTAIN
POPOCATEPETL
Drawn for "Mexico Illustrated" published in 1848 in London.
Many legends have gathered around the old volcano and his beautiful com~anion. The verv names sueeest something of their significance to the Aztec peoples; Popoul "smoke," te@tl "mountain," and Ixtaccihuatl "white woman." These peaks were sacred dwelling places of the gods, unapproachable and secure. Sometimes smoke was seen hovering over Popocatepetl; deep rumblings issued from his throat; the valley trembled a t his feet. These were sure signs of his displeasure, of portending ill fortune. In the year 1519 there was smoke over Old Popoand the first of many invaders was landing a t Vera Cruz. -% .
In the great wall of mountains about the Valley of Mexico, Ixtaccihuatl and Popocatepetl form the barrier on the east and southeast, some forty miles from the City of Mexico. Over the saddle between these peaks passes the highway which from time immemorial has been the path from the sea to the capital. For many years it was believed that Old Popo was the highest mountain on the entire North American continent, as the following quotation from an article by W. V. Wells shows [Har@rs Magazine, 31, 682 (Nov., 1865)l: The summit is undoubtedly the loftiest point in North America -tabular statistics in the Geographies to the contrary notwithstanding-refinements in science which have attempted to snatch the crown from the hoary old god of the Toltecs and place it on the brow of that other storm-monarchof the Russians, Mount St. Elias.
This title was relinquished with great reluctance, especially upon the part of those who were successful in attaining its summit. The expeditions of the Instituto Geologic0 de Mexico have elaced the altitude figure a t 17,876feet.
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Presented before the Division of History of Chemistry of the American Chemical Society at Cleveland, September 11, 1934.
CONQUISTADORES
Even in an age when mighty conquests were remaking the maps of the world, no achievement was more extraordinary than that of ~~~~~~d~coeez and his six hundred men of iron. It was on a Good Friday, April 21, 1519, that the Spaniards landed a t a place w$ch thereafter was to he called Vera Cruz, the gestu, of a conqueror, cortez burned his ships behind him, During the celebrated campaign which carried the invaders to the gatesof the popocatepetl was in a state of unusual activity. The natives regarded this an Omen' To Cortez it appears to have been little more than a curiosity and a party under
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the command of Diego de Ordaz was sent to examine the smoking mountain. Some historians have imagined that it was the purpose of Cortez to flaunt the disdain felt by Europeans for the native superstitions about this sacred peak; to demonstrate that Spaniards were more than a match for these puny gods. In the letter he wrote to his sovereign, however, Cortez simply reported that he wanted to learn the secret of all that smoke. The story of this expedition has been told again and again, - . with an ever-increasing wealth of detail. Long ago it had attained the proportions of a legend and doubts began to arise about the ascent ever having been made a t all. Nevertheless, it must be recognized that in his time and among his fellows, Ordaz was generally credited with having reached the crater of Popocatepetl. His exploit was widely acclaimed and upon his return to Spain he was granted a coat of arms on which his adventure was forever commemorated by a smoking volcano. Some of the conflicting statements regarding the success of this first exploring party may have been due to ignorance of the structure of the mountain. The rim of the crater is quite irregular and the true summit, or highest peak, is a thousand feet above many other points from which the interior may be observed. It is entirely possible that Ordaz did not gain the real summit, but that he did reach the crater and saw therein the molten masses blazing, it is said, like a cauldron of boiling glass. Whatever its fortune may have been, this expedition was long to be remembered and it led directly to another which turned out to he even more remarkable.
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CHEMICALS IN WARFARE
As it was destined, Cortez finally penetrated to the amazing City of Mexico and after a dramatic struggle with the fabled Montezuma, became master of the ancient capital. It was then his purpose to consolidate this advantageous position and to complete the conquest of the surrounding provinces. But in attempting to strengthen the defenses of the city, he was embarrassedfor a time by the hostility of Valasquez, then the Governor of Cuba, who cut off all supplies of fresh military equipment. In this emergency Cortez a t once set about devising ways and means of actually making what was needed. He understood the vital importance of his mysterious weapons. The problem was to find raw materials for the manufacture of the cannon, the projectiles, and the powder. For the cannon, iron does not appear to have been available, although some time later a source of this metal was discovered. There was an abundance of copper, but i t was necessary to find an alloying metal. Tin was known, hut it seems to have been rather scarce, for only the rich were able to afford tin plates and the metal was deemed equal to silver in value. As a matter of fact, in some localities pieces of tin circulated as money. Following up this interesting clue, mines of tin
were discovered a t Taxco. Thus, the ~ ~ a n i a r were ds enabled to make an alloy suitable for casting into cannon and it has been estimated that Cortez was finally prepared to equip his citadel with a hundred large guns. Thirty of these are said to have been made of the copper-tin alloy and the others of iron, an ore of which had been uncovered during the scouring of the nearby provinces. For the projectiles, the scarcity of iron made it necessary to resort to the use of stone halls, a practice not uncommon a t the time. Large, rounded, hard and tough stones were effective after a fashion. The subsequent discovery of iron ores eventually took care of this phase of the problem. For the powder, the necessary ingredients have always been carbon, saltpetre, and sulfur. The first of these, carbon, in the form of powdered wood charcoal, obviously presented no great difficulty. The second requirement, saltpetre, was common enough in the caves of the country. Spanish expeditions in Mexico, and in later years in the American Southwest, often made use of this source, and armies the world over have mined the deposits found in saltpetre caves. And as for the sulfur, Cortez remembered the smoking mountain. MONTANO
The task of removing an adequate supply of sulfur from the crater of a visibly active volcano called for an unusual sort of daring and resourcefulness. No mistake was made when one of the soldiers, Francisco Montano, was selected as the leader of a small party, and the story of this unique expedition deserves a high place in the history of adventure. It is always mentioned in accounts of the Conquest, but there has been some tendency to regard the tale as rather legendary. There are certain pieces of evidence on the subject, however, which cannot easily be explained away. The situation which necessitated a resort to such heroic measures has been described and is a matter of
CHEMICALS FOR CONQUISTADORES Cannon of brass alloy Stone balls Saltpetre from New Mexico Cave Wood charcoal Sulfur from Popocatepetl
record. h"" .over, it can hardly be denied that Cortez got his sui -and his report is quite explicit as to where and L v it was obtained. Finally, the fact that the famili 'of Moutano eventually received official recognition test fies to the opinion of his contemporaries. As will be expla ned in the sequel, most of the foundation upon which doubts were raised has long since been swept away. Minor details in the narrative, gathered from a variety of sources, need not be questioned too critically. The ascent of the mountain was and still is no mean feat in itself and the party led by Montano probably encountered its full share of difficulties. The old volcano had been in a restless state for some time and the bold plans of these daring foreigners attracted a curious crowd of natives to witness the great experiment. A long march on and up through the forest; over the old highway perhaps, with a right turn high up in the pass; then an arduous climb over the black sands, until nightfall caught the Spaniards not far from the snow-line. The ceaseless rumblings and sulfurous exhalations made the darkness most terrifying and dawn was never more welcome, even though it was accompanied by a slight eruption. The band of four or five warriors pushed on for the crater and a t least one more eruption occurred as they progressed painfully up the steep snow-covered cone. At last the rim was attained and a tremendous gulf yawned at their feet. Measurements made in modem times indicate that the width of the crater varies from one to two thousand feet and that its depth ranges between seven and seventeen hundredfeet. There are reasons for believing that the pit was much deeper in the days of the Conquest and that it was far more alarming in appearance. Little or no sulfur was to be found near the rim of the crater and it became necessary for the Spaniards to arrange a descent of the nearly vertical walls which surround the abyss. This difficulty may have been anticipated, or possibly Ordaz had really been there before and had explained something of the peculiar structure. In any case, it is likely that the ropes and the baskets or sacks which had been brought along were merely part of the standard equipment of a prospecting party, as sent out by Cortez. It appears, however, that the man for the business end of the rope had yet to be designated. Lots were drawn and it fell to Montano himself to make the descent. If the plain statement of Cortez is to be accepted, Montano was lowered into the abyss to a depth of seventy or eighty fathoms, equivalent to 420 or 480 feet. Perhaps it should be noted tbat on this particular point there have been some dissenters who were prepared to swallow all the rest of the story. Moutano is said to have made seven trips down the rocky walls, dangling on a rope held by his followers, filling his baskets with chunks of yellow sulfur; and another member of the party, Juan de Larios, has been credited with six descents in the same daring manner. Whatever the depth to which they penetrated, three hundred pounds of sulfur were torn out of the volcano, which at the time
was in a state of turmoil; pouring forth noxious vapors; rolling up smoke from the gloomy interior; erupting showers of ashes and cinders. Fifty kegs of powder were made from the sulfur brought back by this expedition. The emergency soon passed and the exploit was not repeated, for Cortez believed that it would be less trouble to import the things he needed from Spain. Montano was too humble an iudividual to be given the kind of recognition tbat was bestowed upon Ordaz. His claims went unrewarded for many years and it was only after his death that a small grant was secured by his family. Three centuries were to pass before men again set foot on the summit of Popocatepetl. PATrnINDERS
I t was not until the year 1827 that the mountain was again conquered-this time by Englishmen. During the three. intervening centuries there had been a few attempts to scale the challenging peak, but there is no proof that any of them were successful. In 1770, Frederick Sonneschmidt, a German miner, failed in a strenuous effort to gain the summit, although he did make the first barometric observations on the mountain. In 1781, Antonio Alzate, the Mexican naturalist, was forced to give up after a struggle which had brought him scarcely to the snow-line. He expressed the opinion that to reach the summit was simply impossible. This notion came to be quite generally accepted and persisted for many years. Thus it was that when the great Alexander von Humboldt visited the region in 1803, he did not even attempt the ascent of Popocatepetl. His observations and measurements of the mountain were made from the plain near Cholula. Humboldt came to have very grave doubts about the tales of Ordaz and Montano. It seemed to him highly improbable that the Spaniards had succeeded in scaling the mountain and still less likely that they had obtained any sulfur from inside the crater. He suggested that it was some other volcauo they had ascended, one with more reasonable dimensions; or, if it had been Popocatepetl after all, perhaps the sulfur was scraped from some lateral crevice in the mountain. Emanating from the famous naturalist, these ideas gained a rather wide acceptance and have influenced the statements of many more contemporary and subsequent writers. During the past hundred yearscouutless travelers have set foot on the summit and men have lived and worked on the very floor of the crater. Yet opinions expressed a t a time when the peak was considered inaccessible are still often quoted to discredit the stories of the Couquistadores. I t may be that visitors were deterred for some years by the restlessness of the volcano, although only occasionally did it approach a violent stage. Following the disturbances of 1519 and 1523, which the Spaniards observed, another minor outbreak came in 1539. The only severe eruption of modern times occurred in 1664, when for two days a shower of stones and ashes descended upon the countryside. Somewhat milder disturbances
were noted in 1697 and in 1802 and then it was not until the years 1920, 1925, 1932, that the mountain stirred uneasily; the rumblings were just a little louder than usual; and smoke was once more to be seen over Old Popo. The trail-blazing for all modem climbers on Popocatepetl mustbe credited to the Glennies. The party consisted of the brothers, William and Frederick, who were in the service of the British United Mining Company; John Taylour, a merchant of the City of Mexico; and a servant, Jose Quintana. After a struggle which lasted four days, they reached the summit on April 20, 1827. In their project they were assisted by the Alcalde, Don F. Olivares, who owned the mountain, though he had never succeeded in climbing it. A trip up the volcano still remained a strenuous task, but the path had been found and many attempts began to be recorded. The fame of Popocatepetl was so widespread that a climb on this mountain was something to write home about. As the comment of C. J. Latrobe suggests (The Rambler in Mexico, Harper & Bros., New York, 1836, p. 200), the stories that began to find their way into books and periodicals soon presented a bewildering array of facts and fancies. I have seen those who boast of their success, but unfortunately, have not met with one who was sufficiently alive on his gaining the summit to enable h i to convey to others the slightest idea of what he had beheld. SULFUR MINING
Travelers on the mountain up until the year 1849 make no mention of any sulfur-gathering activities more recent than those of the Conquistadores. About the middle of the century, however, schemes to exploit the deposits in the crater were beginning to develop. It is rather surprising to find that even regarding these comparatively modern explorations there are many conflicting accounts. One report has i t that as early as 1836 a resident of Amecameca, Ignacio Reyes, had formulated plans to mine the sulfur in the crater. It is said that his ideas were first tried out in 1849, and certainly it can have been no earlier than that, for no records of sulfur production are found in the published reports of the American soldiers who climbed the peak in 1848. Claims have been made that mining operations were fist started by Juan Mngica of Pnebla, through his administrator, Perez, following a bold descent into the crater by an engineer, Antonio Garcia. Still other records credit the first real examination of the interior to a Senor Corchado, and he is also sometimes referred to as the proprietor of the mountain. The issue has been obscured by the statements of individuals attempting to establish certain titles to this precious property. At one time it is said that seventeen persons were declaring themselves owners of various parts of the mountain, every one of them, of course, claiming the top. Whatever the precise origin of this strange business, there are numerous independent testimoniei to the ex-
THBRANCHOOF TLAMACAS Drawn for the article by W. V. Wells mentioned in the text. istence of fairly regular sulfur mining activities during the eighteen-fifties. Some idea of the trend of events may be gained by noting the observations of visitors to the rancho which was the last habitable spot on the long trail up the mountain. Prior to 1849 this place was always referred to as the "Vaqueria," and, as the name implies, the rude huts served as shelters for cowherds during certain seasons. Located at an elevation of about 12,800 feet, the cabins stood in a small clearing, not far below the timber-line. In the reports of the Glennies these structures were spoken of as being old and dilapidated, but subsequent visitors continued to find it necessary to use them. After 1849 this place became known as the rancho "Tlamacas" and served as the storage depot, refinery, and general headquarters of the sulfur industry. Descriptions are numerous and detailed, for every climber was forced to stop overnight, many of them in prayer and fasting, as a prelude to the final five-thousand-foot struggle up the huge cone. The work in the bottom of the crater largely centered around the "respiraderos," or vents from which steam and sulfurous vapors issued like the breath of some hidden monster. Rocks were piled up around these breathing-holes to aid in the condensation of the sulfur. Hot liquid streams, trickling down over these rock piles, solidified into beautiful yellow masses, which were of a high purity. Deposits of sulfur on the floor of the crater were mined to some extent, but were more or less contaminated with volcanic debris. The material taken from the floor sometimes contained as much as 80% to
90% sulfur, but an ore yielding only from 40% to 50% was more commonly obtained. Accumulations around the vents and deposits on the floor were broken up by the miners, or "volcaneros," as they were called, and loaded into small sacks. These were camed up the steep slope of rock fragments banked several hundred feet high against the sides of the vertical walls. Probably the most iuteresting feature connected with the problem of getting a t the sulfur in Popocatepetl has been the method used to traverse those perpendicular guardians of the interior. To accomplish the descent and ascent of this precipice, Montan0 had been lowered on a rope held by his compauions. When the modern sulfur mining operations were started, "el malacate," the famous windlass, was erected on top of the northeastern wall. It was a simple devices strong rope wound around a cylinder and ran out through a pulley fastened in the end of a stout wooden beam which projected over the abyss. Estimates regarding the height of the wall and the length of the rope have varied in direct proportion to the credulity of the observer. Perhaps the record guess on the depth of the crater was the one which put it a t eight thousand feet, whereas the most reliable figures indicate that the very irregular crown lies between seven and seventeen hundred feet above the floor. Some writers have described two windlasses, the second one on a landing-place half way down the clii, each stage requiring five hundred feet of rope. Probably the most trustworthy reports are those which mention just one windlass, with a rope appropriate for a wall, the vertical portion.of which measured something under three hundred feet. The windlass was made to accommodate both the volcaneros and the sacks of sulfur they had gathered. When about ten sacks, weighing around twenty-five pounds each, had been hoisted by the windlass, they were camed some sixty feet higher to the rim itself and lashed together for the descent of the cone. Weather conditions were an important factor in determining the precise nature of this operation. Sometimes it was possible to maintain a long groove in the snow and allow the sacks to slide down the three thousand foot incline to the snow-lie near "La Cruz." Generally, it was the practice for the workers to perform the dangerous "corrida," which consisted in sliding down the snowy slope themselves, perched on the sacks, or seated on straw mats and dragging down a bundle of sacks with them. A memorial to the many men who met death on the mountain; a shrine a t which to pray for protection on the way up, perhaps to give thanks on the way down. La Cruz, at an elevation of about 14,500 feet, marks very definitely the boundary of the danger zone. From this point it was merely a long weary tramp, packing sulfur sacks down the trail to Tlamacas. At the rancho sulfur was separated from whatever impurities were present in the crude ore by distillation of the material in large jars or kettles. The mining was possible only under favorable weather conditions, but the purification could be carried on in all seasons. The
distillation equipment seems to have been rather small and antiquated, but it was adequate and the product was said to have excelled the Sicilian in quality. From Tlamacas the refined sulfur was transported by burros to Amecameca, thence to the City of Mexico; or to Puebla and thence to Vera Cruz. During the eighteen-sixties, snlfur mining operations appear to have been practically abandoned: Adventurers on Popocatepetl saw remnants of the old refining apparatus, but Tlamacas was a deserted rancho. Still in its place on top of the wall, el malacate was a rickety old machine, about ready to tumble into the crater. The great rope had been badly rotted by long exposure. Not many travelers were about during these years, which were troublesome times in Mexico, as elsewhere in the world. About 1870 possession of the mountain was secured by General Gaspar Sanchez Ochoa, one of the engineers with the exploring expedition sent out by the government some years earlier. He was a close friend of the great Porfirio Diaz who came into power during the seventies, to remain the so-called dictator of Mexico for nearly forty years. During this long dgime, the name Ochoa appears again and again in the reports of visitors to Popocatepetl, for it was necessary to obtain his permission to use the rancho a t Tlamacas as an overnight shelter. The General attempted to revive the sulfur industry, but i t was a discouraging proposition. Operations were maintained a t scattered intervals during the seventies; then for a time were confined to certain favorable seasons; and finally became more and more irregular until they were limited to occasional expeditions. Travelers during the eighties record that Tlamacas was once more desolated and that el malacate had been ruined beyond repair. VOLCANEROS
The mechanical difficulties involved in getting sulfur out of Popocatepetl were far from being insurmountable-the human hazards were intolerable. Natives of the region, accustomed from childhood to physical exertion in high altitudes, were employed for the work, but even on them it was a terrible strain. The thin atmosphere was polluted with choking, sulfurous, acid vapors, which were not only disagreeable but also highly injurious. Even though very liberal allowances of the potent mescal spirits and of the fatigue-banishing coca leaves were provided, it was almost impossible to keep the volcaneros altogether satisfied. The most serious immediate danger in the crater itself was from falling rocks. The excessive freezing and thawing of water in the lava walls produced a tremendous cracking and disintegration. It has been estimated that an average of ten large stones fell every hour, two thousand cubic feet of them per day, piling up on the crater floor and causing it to rise a t the rate of 0.65 feet a year. It is rather iuteresting to note that the pit must have been much deeper in the days of the Conquistadores, and a simple calculation will show that
