1886.1 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 83 



ON FULGURITES. 

 By OKOROE P. ITlERRII.l.. 



(With one plate.) 



Numerous papers on this subject have from time to time appeared, the 

 more recent being those of VVichmann,* Diller, t and Rutley, | the last 

 two treating i)rincipally of fulgurites formed on solid rock while the 

 first named describes both those formed on the solid rock and the 

 tubular varieties formed in loose sand. The subject is by no means 

 a new one. The earliest notices I am able to find relating to it are those 

 given in the Transactions of the London Philosophical Society for 1790, 

 and in the papers of Fiedler and Gilbert in the Annalender Physik for 

 1817 and 1819. Since then periodic papers have api^eared in various 

 journals, not all of which I have had access to and concerning whose 

 contents I have to judge from notices given of them in subsequent pub- 

 lications. 



So far as I am able to learn the most extensive notices regarding the 

 mode of occurrence of tubular fulgurites (those formed in loose sand) 

 are those given by Fiedler,§ Gilbert, Darwin, and Eoeraer, while the 

 chemical and microscopic side of the question, that relating to the com- 

 position and structu^-e of the resultant glass, is most fully discussed by 

 Gumbel, || Harting,** and Wichmann.tt 



Unfortunately none of these gentlemen made complete chemical an- 

 alyses of the purely glassy portion of the fulgurite, and though their pa- 

 pers are full of interest as showing something of the actual composition 

 and structure of the glass, none of them give any information regard- 

 ing this composition relative to the sand in which they were formed. 



The National Museum has recently received from Mr. Silas Stearns, 

 of Peusacola, Florida, Messrs. E. L. and A. N. Abbott, of Union Grove, 

 Whitesides County, Illinois, and Mr. C. T. Mason, of Sumter, South Caro- 

 lina, some very interesting fulgurites of the tubular variety, formed by 

 the lightning striking in loose sand. As these gentlemen furnished full 

 notes regarding the localities and mode of occurrence of these, I have 

 decided to publish in full what information I can glean from them, to- 

 gether with such notes on chemical tests as have been possible under 

 the circumstances, even at the risk of duplicating in part the work of 

 previous observers. 



* Zeit. der Deut. Geol. Gesell., XXXV, p. 487. 

 tAm. Jour. Sci., XXVIII, 1884, p. 252. 

 t Quar. Jour. Geol. Soc, May, ISSf), p. 152. 

 § See bibliography at end of this article. 

 II Zeit. der Deut. Geol. Gesell., 1882, p. 647. 

 *'Ann. de Mines, vol. VIII. 1825, p. 200. 

 tt Op. cit. 



