H. HENSOLDT ON FLUID CAVITIES IN METEORITES. 7 



come under my observation the bubbles suddenly vanished at a 

 temperature of from 30° to 31° C, sometimes even exhibiting that 

 peculiar phenomenon of ebullition to which Mr. Hartley, four 

 years ago, has already drawn attention. Now, if the enclosed 

 fluids had been water, the bubbles would not have shown the least 

 indication of a change at this temperature. I heated a section of 

 quartz, the cavities in which I knew to contain water, to the boil- 

 ing point, without detecting the smallest effect on the bubbles. 



Mr. Hartley, in numerous instances, found water and liquefied 

 carbonic acid in the same cavity occurring in topazes, &c, the 

 carbonic acid, from its lesser specific weight, floating on the surface 

 of the water, and when he warmed the section the carbonic acid 

 would become gaseous at 31° C, leaving only the water in its 

 liquid condition ; but I have made no similar observation in this 

 meteorite. I found only one liquid present, and this in every case 

 appeared to be carbonic acid. 



Among the many chemical tests which have been resorted to in 

 order to determine the presence of carbonic acid in mineral cavities, 

 I will only mention one, which has been quoted already by Mr. 

 Hartley. Vogelsang and Geissler, of Bonn, crushed rock-crystal 

 in which cavities occurred, which they suspected to contain liquefied 

 carbonic acid, under baryta water, and observed that the latter 

 became turbid owing to the formation of carbonate of baryta. 



Now, taking for granted that the fluid material contained in the 

 cavities of this meteorite which fell near Braunfels, is really 

 liquefied carbonic acid, which we may safely do, as it presents no 

 points of analogy to any other known substance ; and that the 

 bubbles, which move so restlessly about in their tiny prisons, are 

 the same substance in its gaseous condition ; what do these facts 

 teach us respecting the circumstances under which the meteoric 

 mass was originally formed ? 



In recent years the belief has been gaining ground that meteor- 

 ites are independent planetary bodies, miniature planets, so to 

 speak, whose formation took place under conditions similar to 

 those under which globes like this earth or Jupiter rose into being. 

 From the fact that numerous planets very much smaller than the 

 earth have been discovered, and that every improvement in the 

 optical efficiency of telescopes adds to their number, and from the 

 fact that streams of planetary bodies of minute size are known to 

 move in regular orbits through the solar system, it is argued that 



