414 Proceedings of the Royal Physical Society. 



may be simply dependent on the rapid cooling, or any other 

 cause which gives the iron its brittle character. Another patch 

 of etching was made near the narrow extremity of the pointed 

 portion of the mass (fig. 2). Here the crystalline structure 

 of crossing lines is less distinct, the metal being apparently 

 more granular in its texture, and exhibiting a series of shining 

 points. The action of the diluted acid on the metal was closely 

 watched, and was stopped occasionally, so as to preserve the 

 appearance of the etching, when its character was most dis- 

 tinct. Wax squeezes and electrotype casts were taken from 

 these etched surfaces, and are here printed from as woodcuts 

 (figs. 1,2). They may therefore be compared with that figured 

 before, which was taken in a similar way from the central part 

 of the meteoric iron. 



A portion of this meteoric iron, with plaster cast of the 

 entire mass, are now preserved in the Natural History Mu- 

 seum, Edinburgh ; the principal part of the iron is in the 

 British Museum, London.] 



Analysis of the Mtteorolite described in the foregoing paper by Dr John 

 Alexander Smith, By Murray Thomson, M.D., F.C.S , Lecturer 

 on Chemistry. 



In giving a chemical description of this remarkable mass 

 of meteoric iron, I have to call attention, in the first place, to 

 its Specific Gravity ; the process of taking which was first per- 

 formed on the undivided meteorite, and afterwards on each 

 of its halves. Of course, with such a weighty mass this 

 process could not be done by means of the ordinary delicate 

 balance. I had therefore recourse to the standard beams and 

 weights contained in the office of the Inspector of Weights 

 and Measures at the County Hall, Edinburgh. The weight in 

 air of the whole mass was 32 lbs., 11 oz., 1J drs., avoirdupois, 

 equal to 39-60 lbs. Troy weight. The weight in distilled 

 water was 27 lbs., 10 oz., 13J drs. This gives a specific 

 gravity, it will be seen, of 6-517, which is very low for me- 

 teoric iron. It stands at the lowest limit of recorded specific 

 gravities of other meteoric irons. Shepard (Silliman's Ameri- 

 can Journal of Science, vol. ii. New Series, p. 377) gives the 



