G58 



SCIENCE. 



[N. S. Vol. III. No. 70. 



pregnated with sulphur, sometimes almost 

 imperceptible to the eye, but oftener ia 

 minute crystals concentrated along irregu- 

 lar lines. Where thus generally dissemi- 

 nated through the brown or chocolate- 

 colored earth, the sulphur makes some 10 

 or 15 per cent, of the whole weight, but 

 where concentrated along the lines above 

 mentioned the percentage of sulphur goes 

 up to 40 or 50 and even higher, for not 

 infrequent is the occurrence of sulphur in 

 the massive form, very light yellow in color, 

 opaque, and of earthy aspect, resembling a 

 3' ell o wish meerschaum, but of exceptional 

 purity, several analyses- of average samples 

 showing 97 per cent, sulphur. The average 

 content of sulphur in the material penetrated 

 by the several pits which were examined by 

 me could not be far short of 50 per cent. 



In the immediate vicinity of one of the 

 occurrences the surface soil is highly 

 charged with gypsum, which appears in 

 small crystals and in large groups of crys- 

 tals imbedded in the white calcareous 

 sandy material rendered strongly acid by 

 the decomposition products of the sulphur. 

 At one place the sulphur beds rest upon 

 an impure limestone which has been so 

 greatly corroded by these acids as to be 

 very difficult of identification. 



Upon exposure to the air the sulphur 

 rapidly undergoes alteration, being in great 

 part finally converted into sulphuric acid, 

 but becoming first opaque and soapy. From 

 this cause the heaps of nearly pure sulphur 

 piled around the mouths of the prospecting 

 pits, rapidly disintegrate and disappear. 

 In many cases, however, this waste has 

 been partly due to the mechanical action of 

 floods which, by reason of the occasional 

 heavy rainfalls, sweep down the generally 

 dry ' draws,' carrying everything before 

 them. The sides of the pits and the ma- 

 terials thrown out of them exhale a peculiar 

 odor (sulphury), and are so strongly acid 

 as to destroy quickly the clothing and other 



organic matters brought iu contact there- 

 with. 



The sulphur beds do not appear to under- 

 lie uniformly the whole basin, for in the 

 region indicated, within a radius of twenty 

 miles, only three places are as yet known 

 where they occur. The actual outcrop by 

 natural or artificial exposure will here 

 cover some four or five acres, but the proba- 

 bility is that the sulphur in each of the 

 localities underlies a much larger area, for 

 wherever penetrated by borings or pits 

 the sulphur-impregnated earth has been 

 encountered to a depth of at least ten feet, 

 and a deposit of this thickness could hardly 

 be conceived to thin down so rapidly as to 

 limit the occurrence of the sulphur to the 

 small area in which it has actually been 

 exposed. 



Nor, on the other hand, are the sulphur 

 deposits of Texas confined to the particular 

 region designated iu these notes, for there are 

 well authenticated reports of their occurrence 

 both to the westward and to the northward, 

 the former from cowboys, through whose 

 representations attention was first directed 

 to the beds above described, the latter upon 

 the authority of Capt. John Pope, who had 

 charge of one of the divisions of the survey 

 of the railroad routes to the Pacific. Along 

 the banks of Delaware creek he collected a 

 sample of earth which contained 18.28% of 

 sulphur, and he comments also upon the 

 frequency of sulphur springs in the same 

 region. Delaware creek rises among- the 

 Guadalupe mountains and flows into the 

 Pecos river some fifty miles to the north- 

 ward of Guadalupe station. 



The materials filling the basins of the 

 Trans-Pecos region have very generally 

 been considered as of lacustrine origin, and 

 of the truth of this supposition we have 

 very good proof in the great number of 

 fresh-water diatoms discovered in the sul- 

 phur-impregnated earth submitted by me 

 to Mr. K. M. Cunningham, of Mobile, for 



