H. HENSOLDT ON FLUID CAVITIES IN METEORITES. 



tains, in almost every instance, a more or less large, roundish 

 body in a state of continual motion. It is evident that these 

 cavities contain a liquid of some sort, that they are, in fact, fluid 

 enclosures, and that the moving bodies are bubbles of a gaseous 

 nature, which are continually driven about by the variations in the 

 temperature of the atmosphere, owing to their exquisite sensitiveness 

 in consequence of their minuteness. The cavities are by no means of 

 a uniform appearance, but exhibit every variety of size and form ; 

 nor does their grouping indicate the least order or regularity. 



In the larger cavities I invariably found the bubbles to move 

 slower, in some very slow indeed, and in the very largest the 

 motion is scarcely perceptible ; but if we examine the medium- 

 sized and smaller cavities, we are startled to observe a very lively 

 motion of the bubble in the interior. Indeed, I may safely say 

 the rapidity of the motion of the bubbles is quite in proportion to 

 the relative size of the cavities in which they occur. 



Now the discovery of cavities in crystals, containing liquid 

 matter, is by no means original, but is very old, as most of us will 

 know. Rock-crystal, amethyst, and other minerals of the quartz 

 type frequently contain liquid cavities, for the detection of which 

 neither microscope nor pocket-lens is needed ; cavities often so 

 large that they have been known to contain several ounces of 

 liquid matter. Even the discovery of microscopic liquid cavities 

 containing moving gaseous bubbles has not been very recently 

 effected, but is at least several years old. Very ingenious 

 attempts have been made to establish the nature of these im- 

 prisoned liquids, and in many, if not in most cases facts have been 

 ascertained from which very safe conclusions may be drawn, 

 although the presence of most of the liquids in crystals has not 

 yet been satisfactorily explained, owing to our still very imper- 

 fect knowledge of the laws which govern the formation of those 

 extraordinary and mysterious bodies, the crystals. 



But the discovery of liquid cavities in a meteorite is, as I have 

 strong reasons to believe, original ; at least, there is no instance 

 on record of its having been previously made ; and in the following 

 I shall attempt to show the importance of this discovery, and the 

 new light which it throws on meteorites, giving support to some 

 theories, while antagonistic to others, respecting the origin of these 

 remarkable objects. 



Four years ago, Mr. Noel Hartley read a paper on fluid cavities 



