1842, June 4th. - Aumieres, Dcp. de la Lozere, France. 1 In an interesting series of papers on the study of rocks, especially as regards the analogies in point of structure and mineral composition which are to be traced between the terrestrial rocks and those met with in meteorites, Meumcr has adopted the following classification for the latter series: 1. Normal; 2. Brecciated ; 3. Metamorphio; 4. Eruptive; 5. Rocks traversed with veins (jUtmnienne* concritioning); and 6. Volcanic* The iron of Deesa (which see) he regards as an example of an eruptive meteorite, the stone of Chantonnay represents the class with veins entirely rocky. The veins of cosmical rocks show as many varieties as terrestrial rocks. The upheaval of rocks on our globe presupposes the existence of Faults, that is to say, of vents which establish iicemmiLiiicMliiin between tin? earth's interior and the atmosphere. Faults are recognised by the throws which the rocks constituting their two sides have undergone ; these rooks, although preserving their continuity, are shifted vertically in masses that may be very considerable. The more the surface of these faults shows traces of violent friction, the more they become polished, channelled, or striated. In the same way meteorites in a number of cases exhibit true faults, with throws and polished surfaces. In the meteorite of Aumieres, of which a representation is given below, one fault is seen to cut another again to which it gives a downthrow of several centimetres. The stone of Aumieres consists of a grey rock, like that forming the meteorite of Aumale (1865, August 25), which possesses the remarkable property of turning bind; when heated. By the friction of such surfaces and the consequent development of heat the adjacent surfaces undergo a true metamorphism. and the grey face as a consequence becomes black. The faults in such cases have the form of black lines which have very much the appearance they would present if traced with a pen. On comparing different fragments it becomes evident that where the throw and as a consequence the mechanical effect have been considerable, the black lines have a more marked character. The thickness indicates the degree of dynamic energy to which the stone has been subjected, and the grey rock of Aumale and Aumieres is in fact an extremely sensitive thermometer of a kind that may render great service in the study of the conditions to which meteorites may have been exposed.
