FHE ULTIMATE SOURCE 



this, in all probability, we owe the preservation of the vast 

 stores of rock salt which now exist. If the presence of salt 

 everywhere is considered an evidence of design in the 

 creation of the world, how much more so is this arrangement, 

 which so effectually preserves it through untold ages of cosmic 

 change. 



In considering the source and origin of common salt I have 

 purposely overlooked one natural feature, possibly concerned, 

 even at the present time, in its formation, namely, chemical 

 agency. I have indicated that originally all the salt which 

 now exists was formed by the chemical combination of sodium 

 and chlorine, previously existing in a state of vapour, and 

 have inferred from recent experiments with chlorine, that 

 this combination could not have taken place until the tem- 

 perature, and pressure, had fallen to a certain point. But I 

 have not reproduced chemical action in later times inas- 

 much as the question under discussion referred to the origin of 

 rock salt, as a geological formation, in which it is evident 

 chemical action could not have been directly concerned. 

 Nevertheless, lest it should be objected to this paper that one 

 existing source of salt formation has been entirely overlooked, 

 I will here glance at the natural chemical formation of 

 common salt, merely premising that it is a local and com- 

 paratively insignificant process. 



Common salt occurs here and there, at rare intervals, on the 

 earth's surface, as an efflorescence ; or, in brine exuding from 

 the base of mountain formations, in no way related to rock 

 salt ; in situations, in fact, in which no common salt was 

 to be expected on any theory previously referred to in this 

 paper. Such deposits are said to exist largely in Chili, and 

 their formation has been studied by M. Pissis, who has drawn 

 up a report on the subject for the Chilian Government. At 

 the base of the Shevaroy Hills, in the centre of the 

 South Indian peninsula, a salt spring or salt lick, used 



