MK. E. W. BINNEY ON THE ORIGIN OF IB0N8T0NES. 39 



ficial crust of the globe and the waters upon it. The ease of 

 the bed of iron before alluded to was mentioned in a recent 

 publication in the following words, " The formation of lodes 

 by sublimation may sometimes be observed at the present 

 day in volcanic mountains. Thus, for instance, during an 

 eruption of Vesuvius, in 1817, a fissure of more than 3 feet 

 in diameter was filled within the space of ten days with spe- 

 cular iron ore deposited from the vapour of chloride of iron 

 evolved."* Numerous lodes of specular iron ore, in different 

 rocks of various epochs, clearly shew that these phenomena 

 took place in many ages of the earth's history just as it did 

 in the case first alluded to, the lodes resembling each other as 

 much as possible. But the chloride of iron from volcanoes 

 in ancient times, when there was most probably much less 

 dry land than at present on the earth's surface, would more 

 frequently flow into the waters of the sea than remain in the 

 fissures of rocks. Subaqueous volcanoes, as the stratified 

 beds of trap and volcanic ashes prove, were then of frequent 

 occurrence. Now the chloride of iron might be ejected in at 

 least three different ways : first, it might be ejected dry into 

 the atmosphere, in which case chlorine and peroxide of iron 

 would result ; next, it might be ejected with vapour of water, 

 in which case muriatic acid and peroxide of iron would be 

 formed ; and thirdly, it might be ejected into water, having 

 lime either in solution or as a deposit. In this last case the 

 lime would take the chlorine and throw down the peroxide of 

 iron, leaving chloride of calcium in solution. In this liquid, 

 if it were at all strong, no living beings could flourish. These 

 eruptions of chloride of iron, at certain periods of the earth's 

 history, would give us some clue to find out the cause why 

 the red coloured deposits are so scantily supplied with organic 

 remains. Both in the old red sandstone and the new red 

 sandstone groups, organic remains, it is well known, are very 

 sparingly found. 



• Edinburgh New Philosophical Journal for October, 1868. No. 110, p. 848. 



