October 30, 1885 ] 



SCIENCE, 



391 



weather is clear, amply compensates for all the 

 difficulties of the ascent. At the feet of the 

 spectator lies spread out like a map the beautiful 

 plateau of Anahuac, over eighty miles long, with 

 its four lakes, and more than 200 cities, villages 

 and haciendas, including Mexico the capital, 

 Puebla, Cholula, Atlixco and Tlaxcala, surround- 

 ed by snow-covered mountains, among which 

 rise the peaks of Ixtaccihuatl, only eight miles 

 distant, Malinche, and farther toward the east, 

 Orizaba. 



The view of the interior of the crater is always 

 completely obscured by the sulphur vapor, which 

 constantly rises from the openings in the bottom, 

 called respiraderos. It is at first of a greenish 

 color, then condenses and falls in yellow drops, 

 and finally forms into beautiful crystals. The 

 edge of the crater is composed of immense blocks 

 of porphyry and basalt. To descend iato the 

 crater, one follows a path leading downwards 

 from the summit among ice-covered rocks, till a 

 huge block of basalt is reached, which serves as a 

 support for the primitive machine, called malacate, 

 which is used here, as in most of the mines of 

 Mexico, for the perpendicular descent of the 

 remaining distance. A strong beam projects a 

 few feet horizontally over the abyss ; over a pulley 

 in the end runs a long rope with a loop in the 

 lower end. The person wishing to descend stands 

 in the loop, holds the rope in one hand, and with 

 the other manages a stick, to protect himself from 

 injury by swinging against the rocks. Two peons 

 let the rope run slowly out over the pulley, and in 

 this way the descent is accomplished. The rope 

 is over 250 feet long, and the descent occupies ten 

 or fifteen minutes. 



The crater has the form of a funnel. The 

 bottom is composed of scoriae, which glitter with 

 various colors, and among which are the respi- 

 raderos. In one place is a stone so large that a 

 man can stand upon it, which rises and faUs as it 

 feels the effect of the subterranean vapors. At 

 the lowest point is a lake, the water of which has 

 a sulphm-ous and also somewhat acid taste. 



The descent of the mountain is, of course, very 

 much easier and quicker than the ascent ; that of 

 the snow-cone especially is accomplished in a 

 very summary manner, familiar enough to a New 

 Englander, to be sure, but rather startling in its 

 novelty to inhabitants of the southern countries. 

 An Indian sits on the forward end of a mat, hold- 

 ing a stick upright between his legs ; the traveller 

 sits behind, clinging to the guide with hands and 

 legs, and in less time than fifteen minutes the dis- 

 tance is traversed, which in the ascent occupied 

 three or four hours. 



According to the latest measurements, the 



height of Popocatapetl is 17,809 feet above the sea- 

 level. The crater is about 2^ miles in circuit, and 

 has a depth of 1,000 feet. Since the mountain 

 has given out sulphurous vapors for centuries, and 

 at the present time something like a ton of sulphur 

 is deposited daily, the amount of the mineral exist- 

 ing there is almost beyond estimation. It would 

 hardly be an exaggeration to say that the upper 

 part of the mountain is an immense block of 

 sulphur, enclosed in a shell of rock a few yards 

 thick. 



Three qualities of sulphur are obtained by the 

 operations here. The best is almost chemically 

 pure, obtained at the respiraderos, whence it 

 issues in a liquid state and hardens as it cools. 

 The other two qualities are known as rich 

 and poor sulphur-ore. The former yields from 

 82 to 87 per cent of pure sulphur, the latter 

 about 50. 



The process used for the purification of the 

 sulphur is that of Michel, with the apparatus im- 

 proved by Lamy. The distillation takes place in 

 six large cast-iron kettles, or haK-cylinders, which 

 take the place of retorts, and a large brick chamber 

 which serves as the receiver. 



Since the sulphur of Popocatapetl is much 

 superior to the Sicilian, it is in greater demand in 

 the American markets. The works at Tlamacas 

 have control of enough water and fuel to increase 

 their productiveness considerably. This would be 

 in every respect advantageous ; aside from the 

 consumption of Mexico, the United States use 

 200,000 tons annually, and even if every ton were 

 sold 20 per cent below the usual price, there 

 would stiU be, after allowing for freight and all 

 other expenses, a clear profit of two dollars a ton. 

 The expenses of production are very small. The 

 workmen receive only about 75 cents per arroha 

 (25 pounds), although their work is laborious, 

 dangerous on account of the constantly falling 

 rocks, and from breathing the sulphm-ous vapors 

 very deleterious to the health, causing in a short 

 time, among other inconvenience, the falling out 

 of the teeth. 



The principal source of the world's supply of 

 sulphur at present is Sicily, which produces fom'- 

 fifths of that consumed. The deposits of Popo- 

 catapetl are greater than those of Sicily, and, as 

 already stated, of better quality. It seems in- 

 credible that they have not been more thoroughly 

 worked, especially as tliis sulpliui* can be brought 

 to market 25 per cent cheaper than the Sicilian, 

 at least in the United States. 



A plan is now on foot to lead a tunnel tlu-ough 

 the wall of the crater du-ectly to the sulphur 

 deposits, and connect its mouth by a nan'ow- 

 gauge raih'oad with Amecameca, which is on one 



