446 M. Haidinger on the Original Formation of Aerolites. 



stratum, and with it the sphserosideritic agglomeration, under- 

 goes pressure, which, if sufficient, leaves in the interior a softer 

 portion, more impregnated with water than the external crust 

 from which that element has been squeezed more completely out. 

 The sphserosiderite is naturally inclined to assume throughout 

 the consistence of the external crust, which, like a vault or arch, 

 acts in every direction against further contraction. Contrac- 

 tion ensues, and the fissures produced in consequence are subse- 

 quently filled up with crystalline deposits of substances held in 

 solution by liquids penetrating, or already contained within, the 

 interstices. At first magnesian carbonate of lime, then calca- 

 reous spar (occasionally also iron pyrites) are separated and 

 deposited. Certainly there seems to exist a great analogy 

 between the process of formation of such septarise and that 

 admissible as going on within a large pulverulent globe freelv 

 suspended in space. There is indeed no external pressure, but 

 every stratum of ponderable matter exercises compression on the 

 whole. 



The following figure (fig. 4) is taken from Professor C. Koppe's 

 " Physik und Meteorologie " (in Badeker's collective publication, 

 Die gesammten Naturwissenschaften). A point A, attracted at 

 the surface by a material point B as a sum of many others, 

 undergoes also attraction from another point D in a similar 

 situation. The resulting line of direction falls between B and 

 D, and passes through the centre C, along the line C E. 



No determinate direction could pre- „. 



vail in the centre itself, where the mass 

 of the sphere is uniformly distributed, ^^r~~^^ 



and there the action of gravitation would jr /i\ ^S. 

 completely cease (or be in equilibrium). G /~ / T"\ \* 

 As each particle on the surface tends to / / \ \ 



sink towards the centre, it finds an ob- { / !(. \ j 

 stacle from another immediately subja- V / \ / 



cent, this from a third, &c, and this ob- V 3 B J 



stacie must be overcome or removed. N. >/ 



The particles, at first unconnected, join eT""*^^ 



or approximate more and more slowly ; 



pressure is beginning and increasing. As on the surface of our 

 globe, so we may suppose to have existed in meteorites, combina- 

 tions of heterogeneous elements very different from each other 

 in their specific gravities. Among other substances found in 

 meteorites are oxygen, sulphur, phosphorus, carbon, chromium, 

 silicium, hydrogen, cobalt, nickel, iron, aluminium, magnesium, 

 calcium, potassium, — all of them extremely discrepant in density 

 and other physical qualities. It is doubtful whether these ex- 

 isted as elementary particles, or in chemical combinations. In 



