Ordinary Meeting, October 30th, 1883. 



J. P. Joule, D.C.L., LL.D., F.KS., &c., Vice-President, in 



the Chair. 



" On the Action of Water upon beds of Rock Salt," by 

 Thomas Ward, Esq. 



During the last century, but more especially within the 

 past few years, a number of interesting phenomena in 

 connection with the action of water on beds of salt have 

 presented themselves in the Salt Districts of Cheshire. I 

 propose in this paper to examine these phenomena, and to 

 show how fresh water acts upon rock salt, and to point 

 out the results of such action : — 



The various beds of rock salt, in whatever geological 

 formation they exist, are clearly crystalline deposits from 

 the saturated brine of salt lakes. In the dry season, when 

 a salt lake, owing to the evaporation of a portion of the 

 water, becomes saturated brine, salt crystals form on the 

 bottom, under water, and continue to grow and increase as 

 long as the evaporation continues. This is well illustrated 

 in Lake Sambhur, and a number of similar lakes in Rajpu- 

 tana, also in salt lakes near the Caspian Sea, and in many 

 other parts of the world. As soon as the wet season arrives, 

 and the water from the brooks and rivers, bearing down 

 mud, enters into the lake, the beautiful sharp angles of the 

 crystals of salt become rounded off, and the fine mud enters 

 into all the interstices amongst the crystals, and forms an 

 amorphous mass of salt and clay, which is called rock salt. 

 In some portions of the mass, salt prevails, in others, mud. 

 Rock salt deposits var)^ from nearly pure salt, such as is 

 mined for trade purposes in Cheshire, and which was 

 evidently deposited when a longer period of dry seasons 

 Proceedings— Lit. & Phil. Soc— Vol. XXIII.— No, 2.— Session 1883-4, 



