Objects and Uses of Meteorology, 147 



for a considerable time (perhaps four or five years) in a cup- 

 board. Upon accidentally examining it, I found a portion of 

 the acid had escaped, and the gold crystallised. This effect 

 had probably been promoted by a flaw in the vial, which ex- 

 tended through the neck, and a little way down its length. 

 The stopper, in consequence, must have been slightly 

 loosened, and thus allowed more space for the formation of a 

 thin dendritic crystallisation of the gold. This was further 

 continued down the inner surface of the vial, and was there 

 sufficiently thick to admit the impression of minute but dis- 

 tinct crystalhne facets. A small crystallised lump of gold 

 lay at the bottom of the vial ; but I believe this had been 

 originally attached to the rest, and merely fallen by its weight, 

 as I have since observed to be the case in another portion. 

 Around the stopper, and along the flaw, there was a saline 

 concretion, which tasted like sal-ammoniac, and as ammonia 

 was kept in the same cupboard, it had probably united with 

 the muriatic acid as it exuded. Upon finding this specimen, 

 I examined some other metallic solutions, and found a 

 similar separation of the metal had taken place in a vial 

 containing a solution of platina, and in another containing 

 a solution of palladium. In both these cases, a thin, inter- 

 rupted, and dendritic lamina of metal might be seen between 

 the stopper and the neck; but the crystallisation had pro- 

 ceeded no further. I unstoppered the vial containing the 

 platina, and the lamina (as might have been expected) imme- 

 diately disappeared in the form of a slight muddy film. The 

 palladium I still possess. Probably this phenomenon may be 

 of frequent occurrence ; but as the separation of the metal 

 does not often extend below the neck of the vial, it may have 

 passed unnoticed. These facts, if multiplied, may, perhaps, 

 serve to throw some light upon the mode in which the den- 

 dritic laminae of native gold, silver, &c. are formed in rocks. 



Art. XI. Introductory Shetch of the Objects and Uses of Me* 

 teorological Science, By E. W. Brayley, Jun. A.L.S. 



The narrow limits within which our knowledge of the 

 physical constitution of the planet we inhabit is confined, 

 have been frequent subjects of remark with general writers on 

 Natural History. Little more of " the great globe " is cog- 

 nizable to us than the configuration of its surface, with the 

 vegetable productions which invest that surface, and the ani- 

 mals by which it is peopled ; the affections, arrangement, and 



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