448 M. Haidinger on the Original Formation of Aerolites. 



elevation of temperature in conducting the experiment took 

 place too rapidly. 



When chemical action has once commenced, a continuous 

 increase of temperature easily takes place, till, beneath the upper- 

 most dry and pulverulent surface still exposed to the intense 

 cold of cosmical space, a crust or shell has been formed, within 

 which the atoms of matter, following the influence of their own 

 peculiar forces and properties, unite in chemical combinations, 

 and individualize themselves into separate crystals whose elevated 

 temperature (chemical action having ceased) effects more or less 

 lithoid consistence. 



The attempts to explain the central heat of the Earth by means 

 of electrical and chemical action come near the views enounced 

 by Sir Charles Lyell, Prof. De la Rive, &c. (see Naumann, loc. 

 cit. p. 63), while the compressive action of the uppermost terres- 

 trial strata, here taken for a point of departure, is quite adequate 

 to the conditions required by an uninterrupted process of induc- 

 tion. The above-named mobility of particles once admitted, the 

 frequent occurrence of globules in meteorites is no longer a mat- 

 ter of surprise. These globules, sometimes rather regularly 

 rounded (as in some oolites), and in other cases angular or frag- 

 mentary (with edges occasionally rounded at the same time, 

 however), are imbedded in an agglomeration of looser and fre- 

 quently arenaceous particles, for which I have proposed the name 

 of "meteoric tufa*." The surface of these globules is charac- 

 teristically surrounded with particles of iron, as in the meteo- 

 rites of Seres, Assam, Renazzo, Parnallee, and others. The 

 meteorites presenting the aspect of crystalline rocks unmixed 

 with native iron, as in those of Chassigny, Juvenas, Shalka, 

 &c, stand far higher in the scale of development than even 

 those most compact meteorites which include minute particles 

 of metallic iron dispersed through an arenaceous, granular, 

 or tufaceous aggregate of lithoid substance. The highest stage 

 of development is exemplified by the pure and highly crystalline 

 meteoric irons, partially resembling the contents of metalliferous 

 veins (as in the Agram iron), and partly surrounded in all direc- 

 tions with smooth surfaces, a still unexplained circumstance even 

 if superficial oxidation during their progress through the terres- 

 trial atmosphere is taken into account. Instances of a vein-like 

 disposition of metallic iron (as in the Macao meteoric stone), or 

 of iron pyrites (in those of Pegu, Allahabad), as well as genuine 

 planes of fissure (Stannein), rough (Allahabad), or specular 

 (Ensisheim, Lixna, &c), exactly like those in our terrestrial 

 rocks, are of no rare occurrence in many meteorites. The me- 



* See Haidinger's paper, " Das von Herrn Dr. Auerbach entdeckte 

 Meteoreisen von Tula," Imperial Academy, Meeting of November 29, 1860. 



