...',',__. ,t Anhydrous sulphate of magnesia .... 20' 11 , u Common salt 0' 19 Oxide of iron 0-32 ,' 99-20 This mineral occurs in the beds of rock salt at Ischel,...mineralogists as muriacite ; and under the name of Jibrous muriacite, it has been described as a variety of that mineral substance. .- ;. 'MHOT ' •...