472 
PETROLOGY: G. P. MERRILL 
Proc. N. a. S. 
15 Neues Jahrbuch Min. PeL, 2, 1895 (229-246). 
16 —, 1897 (259-61). 
17 Centralhlatt Min., etc., No. 21, pp. 641-47. 
18 Die Meteoriten von Hvittis u. Marjalatti, Helsingfors, 1903. 
19 Trans. Royal Astr. Soc, Canada, 1904. 
20 C. R. Paris Acad. Sci., 96, 1883 (868). 
21 Die Meteoriten in Sammlungen, etc., 1885. 
22 N. Jahrb. Min., etc., I, 1884 (18-43). They immersed fragments of an "olivine- 
fels" for many hours in a slowly cooling melt of nephelin basalt. The stone was strongly 
attacked and the outer portions, in close contact with the melt, shattered and corroded, 
the olivine granules becoming filled with embayments and enclosures of a secondary 
colorless glass, all strongly suggestive of meteoric chondrules. 
23 Studien uber Meteoriten, p. 35. 
24 Zs. Anorg. Chem., 69, 1910 (52-96). 
25 Records Geol. Survey India, 43, 1913 (45). 
26 Such forms may readily be artificially reproduced by fusing to a bead some readily 
fusible mineral like stibnite. Although unfortunately opaque the radiate structure 
may be plainly seen on a broken surface of the globule. 
2' Mikro. Beschaff, der Meteoriten, plate 15. 
28 Proc. U. S. Nat. Mus., Washington, 44, 1913 (326). 
29 Borgstrom and Ramsay in their description of the Bjurbole stone (Bull. No. 12, 
Com. Geologique Finland) mention the irregularity in form of the chondrules, as seen 
in thin sections. They say, p. 18 under (6) Polysomatische Olivinchondren mit Nickel 
eisen "Die Chondren dieser Art haben selten regelmassig runde Form." and again, 
on p. 19 under (8) Chondren aus Glas mit wohlbegrenzten dicken Olivinen, "Sehr selten 
besitzen die Chondren von Typus (8) regelmassige rundliche Begrenzung, sonder- 
nerscheinen in den meisten Fallen mit Zufalligen eckigen oder buckligen Formen." 
3 0 In figure 1, of plate 8, of his Mikroskopische Beschaff enheit, Tschermak shows a small 
monosomatic chondrule inclosed in a larger porphyritic form of the same mineralogical 
composition, from the stone of Dhurmsala. It is to be noted, however, that while 
the smaller monosomatic form is evidently the direct product of a cooling molten magma, 
it has no necessary connection with the ground in which it is embedded and there is 
nothing in the appearance of the larger form, so far as can be judged from the figure, 
to indicate that it is not merely a rounded fragment of some pre-existing chondritic 
stone. This explanation will not, however, hold good for the double chondrule in the 
Borkut stone shown in figure 2 of his plate 19. In the case of our figure 3, plate 3, 
from the Okechobee stone there can be no question but that the chondrule is merely a 
fragment inclosing a large enstatite. 
31 I find no reason in the criticisms of Quirke {Economic Geology, 14, 1919 (621)) to 
change my oft expressed views regarding the origin of the metallic iron through the 
reduction of lawrencite or some other easily reducible compound. Chlorine is a gas 
and in a dry atmosphere would readily escape of itself and without evident action on 
the silicate constituents. If means were to be "provided" it would have to be for the 
retention rather than for getting rid of this constituent. 
32 C. R. Paris Acad. Sci., 13, 1841 (48). 
33 Jour. Proc. Roy. Soc, New South Wales, 36, 1902. 
