Intelligence and Miscellaneous Articles. 79 



to the oolitic hills. He assumed that in the event of a coral-area 

 becoming one of sedimentary deposition, the sedimentary deposit 

 would preserve intact the contour of the coral islands, and inferred 

 that this has been the case in the Bath district, so that the Great- 

 Oolite cappings of the hills of that area may represent the original 

 contours of coral islands, exposed by the denudation of the Brad- 

 ford clay. The amount of denudation undergone by the Great- 

 Ooliteli mestone he considered to be very small. The Inferior 

 Oolite, on the contrary, he believed to have suffered denudation ; and 

 he considered that the course of the valleys formed by this agent 

 was dependent on the form of the limestones capping the hills. 



X. Intelligence and Miscellaneous Articles. 



ON THE MICROSCOPIC STRUCTURE OF HAIL. 

 BY PAUL REINSCH. 



ALTHOUGH the formation and origin of hailstones must be 

 counted among the meteorological phenomena which have not 

 been fully explained, yet its differences from other atmospheric deposits 

 (as, for instance, in structure) show that in its formation causes are at 

 work which in the formation of other atmospheric deposits are either 

 entirely wanting or only operate in less degree. Yet from the differ- 

 ence in hailstones as regards form, magnitude, and internal structure 

 it must be concluded that the same causes are not always at work. 

 In any case, in order to give a theory which shall completely explain 

 the phenomena, it is important to know all types of hailstones ; more 

 especially does the microscopic structure offer many criteria for a cor- 

 rect theory. In this subject of meteorology, as in many other 

 branches of science, the microscope has a future before it. The 

 present notice has reference to the microscopic structure of the hail- 

 stones of a storm which passed over part of the Westrich in the 

 afternoon of June 8, 1869, a few days before the fall of the Kraken- 

 berg meteorite. The hailstones had a diameter of 10 to 12 mil- 

 lims., were almost exactly spherical, and appeared to have rather a 

 concentric than a radial structure. An individual stone laid upon 

 the object-table of a microscope was seen to be made up of individual 

 corns or granules all of nearly the same size, in the middle of each 

 of which was a single minute bubble with a brighter core and darker 

 periphery. The individual granules are ordinarily round, but some- 

 times elongated ; they are bounded by a well-defined line, and are 

 sharply separated from each other ; so that part of a hailstone shows 

 some similarity to the merenchymatic structure of the vegetable 

 cell ; the substance of the grain itself is quite homogeneous and free 

 from structure*. As the hailstone gradually melts on the surface 

 of the object-table the following remarkable deportment is observed. 

 The darker sharp contour of the granule disappears at the fusion-line 



* I was unfortunately unable to observe the structure of the solid sub- 

 stance of the grain in polarized light. 



