38 



paper they had jnst heard read, he considei'ed it might be of considerable 

 interest, and not altogether wide of their more special studies. 



Mr. J. D. Hardy inquired if the sections had been examined with the polari- 

 scope, and whether the appearances might not be caused by " Brownian " 

 movements ? 



Mr. T. H. Buffham thought that no proof had been given that the cavi- 

 ties contained carbonic acid. He doubted that any quantity of carbonic 

 acid could be retained in such sections under the pressure required to 

 liquify it. He thought that the contents might be water formed by a com- 

 bination of hydrogen with the oxygen of the iron. The conclusion that the 

 meteorite was part of a larger one that had been exploded was also against 

 the general opinion regarding the formation of the asteroids and similar 

 bodies. It had been proved that these could not have been produced by such 

 an explosion, as the asteroids had no common node. In the neighbourhood 

 of the sun there were millions of such bodies, space being filled with 

 bodies of all sizes. No known power could separate the smaller fragments 

 of an asteroid or meteorite from the larger. Meteorites were considered 

 to be aggregations of smaller bodies, not the result of explosions. 



Dr. Matthews asked if the cause of the high temperature of the meteor- 

 ite was known ? 



Mr. Hensoldt, in reply, said that the movements of the bubbles were 

 clearly not " Brownian," but were caused by variations in the atmospheric 

 pressure. The same effect could be shown with a delicate spirit-level. The 

 rapidity of the motion was in proportion to the smallness of the cavities. 

 He had not been able to examine the fluid with the spectroscope, but had 

 come to the conclusion from its behaviour that it must be either carbonic 

 acid or some hitherto unknown substance of the same character. Cavities 

 in basic lava had been found to contain carbonic acid. His investigations 

 tended to support the explosion theory. The heating of meteorites was most 

 probably caused by friction in their rapid passage through our atmosphere. 



The President, in closing the discussion, referred to a paper " On the 

 Identification of Liquid Carbonic Acid in Mineral Cavities," by W. N. 

 Hartley, F.C.S., read before the Boyal Microscopical Society (Monthly 

 Mic. Journ., vol. xv., 1876, p. 170), and placed the volume on the table 

 for reference. He called upon them to pass a cordial vote of thanks to Mr, 

 Hensoldt for his elaborate and interesting paper. 



A vote of thanks was carried unanimously. 



The President announced the engagements for the ensuing month, and 

 the Proceedings terminated with the usual Conversazione, at which the 

 following objects were exhibited : — 



Section of Coprolite ... ... ... Mr. F. W. Andrew. 



Floscularia ... ... ... ... Mr. W. G. Cocka. 



Head of Carpenter Bee (Odynerus parietum), 

 showing organs of mouth in natural form 

 and colour ... ... ... ... Mr. F. Enock. 



Fluid enclosures in a section of a Meteorite (in 



illustration of his paper) ... ... Mr. H. Hensoldt, 



Attendance — Members, 44 ; Visitors, 2, 



