412 0. Poulett Scrope — Note on Mr. R. Mallet. 



Found 1853. — Tazewell, Claiborne Co., Tennessee. 1 



This meteorite was one of those selected, by the author for- his 

 investigation with the spectroscope of the gases occluded by meteoric 

 iron (see also the meteorites of Eed River, Texas, and Arva, Hungary). 

 It is noted for the large amount of nickel, 14-62 per cent., which it 

 contains ; it had been examined by J. L. Smith, 2 who found no 

 carbon in it. As in the case of the Texas meteorite, this iron 

 appears to evolve gas at ordinary temperatures ; the red and green 

 hydrogen lines were brilliant, while the bands of carbon were 

 not noticed. "When heat was applied, the spectrum showed the 

 hydrogen lines very brilliantly, and the four chief carbon bands 

 were strongly marked. As the tension of the gas decreased, the 

 hydrogen lines became relatively brighter and the carbon bands grew 

 narrower ; and at 1 mm. these bands were still prominent, while 

 some narrow bands apparently belonging to nitrogen were observed. 

 They diifered however somewhat, as to the order of their relative 

 intensities, from those observed with nitrogen alone. One of the 

 lines appeared to coincide with the chief coronal line 1474 K, although 

 it was not so sharp as it appears in the solar spectrum. An oxygen 

 line, likewise observed, has the position 1462 K very nearly, and 

 closely agrees in point of refrangibility with a bright coronal line 

 noticed by Denza and Lorenzoni during the eclipse of the 22nd Dec, 

 1 870. A second oxygen line, less bright but sharp and distinct, has the 

 position 1359 + 1K. The author directs attention to the complete 

 change which the spectrum of an air-tube undergoes by the intro- 

 duction of hydrogen. According to the method by which Wright 

 calculates the amount of gas present in an iron (see the meteorite 

 of the Eed River, Texas, page 364), this metal occludes 4 - 69 times 

 its volume of mixed gases. Although the greater part of the gas had 

 been removed, the author is of opinion that the whole amount was 

 by no means exhausted. The fact of the volume of gas in this 

 instance being in excess of that obtained by Graham and Mallet 

 probably arises from the Tazewell iron having been in a finely 

 divided state, and his latest researches on the iron enclosed in the 

 meteorite of Iowa (1875, February 12th) support this assumption. 

 (To be continued in our next Number.) 



IV. — Note on Mr. R. Mallet on the Prismatic Structure 



op Basalt. 

 By G-. Poulett- Scrope, F.E.S., F.G.S., etc. 

 R. R. MALLET'S paper on this subject, of which an abstract ap- 

 pears in the Proceedings of the Royal Society, as read January 

 21, 1875, lays claim to a certain amount of originality in the views 

 propounded by him, to which, as well as to the correctness of some 

 portion of them, exception must be taken; though it may be that the 

 conciseness of an abstract will to some extent account for what appears 

 imperfect in its reasoning. For this reason no attempt will be made 

 here to review in detail the general theory announced by Mr. Mallet 



1 A. W. "Wright. Amer. Jour. Se., 1875, ix. 294. 



2 J. L. Smith. Amer. Jour. Sc, [2], xix. 153. 



