Hidden — Mineral Research in Llano County, Texas. 433 



sunlight, and after two or three days of this kind of mining a 

 redness of skin and a burning sensation would be followed by 

 actual soreness of the parts of my hands and face exposed to 

 the direct emanations from the minerals. My assistant (Mr. 

 J. Edward Turner) complained of it also, and asked me " if 

 these minerals could be poisonous ?" As no arsenic was pres- 

 ent, the soreness which we both experienced might possibly 

 have been caused by free fluorine, but not by any soluble con- 

 stituent of the mineral, since salts, such as would be dissolved 

 by the moist skin, had long ago been dissolved, leached out 

 and redeposited in the " chimney " of the mine. It was some 

 time after this that the thought came to me that this action 

 might be the work of a radio-active element and it is offered 

 now more as a suggestion than as a proven fact. I incline 

 strongly to the idea, however, of my having actually experi- 

 enced the proof of the presence of a very high degree of 

 radio-activity, of a peculiar if not unique kind, at this mine, 

 and that the symptoms above described go a long way towards 

 proving it. Of the true nature of this activity I will not at 

 this time offer any conjectures, but will defer a discussion of 

 it to a paper which is under preparation relating to this very 

 interesting region. 



Many photographic records were taken of these " stars," 

 and one of them is shown in fig. 4 ; they are sometimes eight or 

 ten feet across. Although these radial lines are not new to 

 science, having often been noted elsewhere in connection with 

 allanite, monazite and other rare species, it is not likely that 

 they have been before observed on so large a scale. The cause 

 of this phenomenon has not been determined, so far as I am. 

 informed, but it is not without interest that these radial lines 

 are noted only with certain minerals containing rare elements 

 and are most conspicuous with the radio-active species. 



Am. Jour. Sci.— Fourth Series, Vol. XIX, No. 114. — June, 1905. 

 30 



