1888.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 165 



constituents, as they existed in the fresh rock, can not be estimated 

 with any degree of certainty from the figures as above given for the 

 reasons already stated. 



The structure of the stone above described is of sufficient interest to 

 merit further attention. As is well known Dr. Forbes, as early as 1872,* 

 taught that in microscopic structure many meteorites resembled ter- 

 restrial tuffs ; that they were formed of the debris of some previously 

 existing larger mass, of the ruins of some planetary body. The same 

 year Tschermak t described the Gopalpur meteorite as consisting of 

 a white, earthy, tuff-like grouudmass, carrying fragments aud " ku- 

 gels " of bronzite, olivine, and other minerals. Such a fragmental struct- 

 ure, he argued, could have been produced by the friction of the con- 

 stituent particles between themselves, whereby the more brittle became 

 ground to powder, while the more tenacious remained as kugels, the 

 whole being finally gathered into a loose agglomerate. Again, in 1874, | 

 he taught that many meteorites are of a fragmental nature, are made 

 up of minute flakes aud splinters and rounded globules. Later, in 1878, 

 the same authority § described the Grosnaja meteorite as a tuff, the 

 chondri showing that the stone had uudergoue two distinct phases of 

 formation: (L) a breaking up and trituration of the origiual olivinfels, 

 aud (2) an elevation of temperature accompanied by reducing vapors. 

 Drasche* || too, in describing the Lance stone (which, in many respects, 

 is closely identical with the one under consideration, as shown by his 

 figures and description), speaks of it as having a tuff-like grouudmass, 

 carrying olivine aud bronzite kugels and fragments, and Keuschff in 

 describing the Tysnes stone, speaks of it as a conglomerate made up 

 of conglomerate fragments. He regards the typical chondri as but 

 small rounded fragments and their form due wholly to external cause, 

 not to internal structure. Within the past year Bosscha** has described 

 the meteorite of Karang-Modjo, or Magetan, Java, as an agglomerate of 

 cosmical substances that have become cemented together. From the 

 fact that the iron occurs in part as granules, and in part in the form of 

 a cement, he infers that the stone originated under a variety of condi- 

 tions of temperature; that it is not the result of a single fusion and 

 crystallization, but that the various chondri originated separately aud 

 isolated from one another. 



On the other hand, Dr. Wadsworth, who has devoted more attention to 

 the subject than any other American petrographer, aud to whom we are 

 indebted for an excellent review of the subject,tt states it as bis belief that 



*Geol. Magazine, 1872. 



tMin. «. Pet. Mittheil, 1872, p. 98. 



tSitz. der Kais. Akad. der Wiss. Math. Natur., CI. LXXI., 1, II, 1875, p. 661. 



$Min. u. Pet. Mittheil., 1, 1878, p. 153. 



|| Min. u. Pet. Mittheil., 1875, p. 6. 



IT Op. Cit., p. 473. 



**Nenes-Jahrb., v, Beil Baud, 1877, 1st Heft, p. 126. 



ttLithological studies, p. 106. 



