121 



of lava from the great crater of Kilauea, in Hawaii, one of 

 the Sandwich Islands. 



He remarked that this lava is distinguished for its ready fusi- 

 blHty, and is a true glass, with ferruginous, calcareous and alka- 

 line bases.. It is well known, from the descriptions of travellers 

 who have visited this volcano, that the crust of indurated scoriae 

 becomes suddenly melted by the imprisoned heat of the volcano, 

 and that, when thus liquified, it is tossed about by the escaping 

 gases, so as to represent an immense caldron of boiling igneous 

 fluid. Each explosion of gas or steam throws off masses of 

 semi-indurated lava, which draw after them delicate filaments 

 resembling finely-drawn green glass, and these glassy fibres are 

 driven by the wind into heaps, at the sides of the crater, where con- 

 siderable quantities may be collected. The natives of Hawaii call 

 it the hair of Pele, the demigod of the mountain, who is sup- 

 posed by them to tear her hair with rage when the volcano is in 

 eruption, and they formerly endeavored to appease her wrath 

 by throwing a hog into the crater. This curious supei'stition is 

 now becoming; obsolete throuorh the influence of the missionaries. 



This analysis was made, under Dr. J.'s directions, by his friend 

 and pupil, Mr. Joseph Peabody, of Salem. The alkalies were 

 separated from the filamentous lava, or Pole's Hair, by himself. 

 A slight overrun in the analysis may be imputed to the greater 

 purity of the volcanic glass in its filamentous state. 



Several lots, of 25 grs. each, were analyzed with the following 

 results per cent. : 



25.975 

 6.5381 ^ f, 



2.078 ^^y^- of bases, 

 2^923 I 13.067 



1.017 I 

 0.511 J 



100.28 



It will appear, from this analysis, that the ratio of the oxygen 

 of the acid is to that of the bases as 2 to 1. Hence the lava is 

 a bisilicate of those bases, or (Fe Ca Al K N) Si^, or Fe Si -f- 

 ( Al Ca K N) Si. 



It is probable that this lava will make good bottle-glass. 



PROCEEDINGS B. S. N. H. 13 JULY, 1846. 



