Analyses of Lavas. 33 



Before leaving the brief account of the common external forms of lava, it maj' be 

 of interest to the reader to have before him some of the analyses of the Hawaiian lavas as 

 given in ni}' former essay on the Hawaiian volcanoes, and in more recent publications: 



100.9 99.5 99.61 99.67 100.28 99.89 99.19 99-23 100.95 99.37 



Of the.se analyses A was of dark bottle-green lava drops from Halemaumau. 

 Dr. C. T. Jaclcson. 



B. Pele's hair, Kilauea, 1864. Both protoxide and peroxide of iron were 

 present, bnt owing to the presence of oxide of manganese the proportions were not 

 determined. J. C. Jackson. 



C. Pele's hair, Kilauea, 1840. B. Silliman, Jr. 



D. Pele's hair, same source and analyst. 



E. Pele's hair, light colored. Analyzed b^- J. Peabody. 



F. Recent vitreous basalt, fresh and unaltered. Silvestri.'^ 



G. Older basalt, but fresh. Silvestri. 



H. Older basalt, much altered. Silvestri. 

 I. Compact basalt-obsidian. Cohen.'' 

 K. Pele's hair. Cohen. 



Another form of lava has been found and may be found again, a fragment of 

 which is shown in Fig. 29. In a blow-hole the late Mr. H. Rexford Hitchcock found 

 some specimens which seem to me to have been formed by an electric current acting 

 on a plastic mass containing much iron. The masses are of considerable specific 

 gravity (2.857), and the surface is arranged precisely as iron filings place themselves 



'^'Comitato Gcologico d'ltalia, BoUetiiio, i88S, xix, 128, 168. 

 "X. Jahrbuch fiir Mineralogie, etc., 1880, ii, 23. 



Memoirs B. P. B. MrsEUM. Vol. II, No. 4.-3. L4' ' J 



