Lt.-Gen. McMahon—The Rape of the Chlorites. 113 



But if we are at liberty to suppose, for the sake of argument, 

 that none of the iron, or alumina escaped from the chlorite, what 

 brought the extra alumina, potash, and iron to the spot ? Why 

 should these bases have left other cooler and more comfortable 

 localities, in which they were located, to force their way to the 

 centres of molecular disturbance where crush, shear, and intense 

 heat prevailed ? 



If the distressed chlorites had been beautiful females and the 

 iron, potash, and alumina, ardent male creatures one might have 

 accounted for their rushing through fire and smoke to reach these 

 prizes, like Roman soldiers engaged in sacking a town, but I 

 suppose the author is not prepared to endow his molecules with 

 sexual qualities, and, in the absence of any explanation of that kind, 

 I confess that I cannot imagine the nature of the fascination which Dr. 

 Callaway's distressed chlorites appeared to have had for the iron, 

 the potash, and the alumina situated in other parts of the rock ; 

 nor can I imagine the agency by which these bases were conveyed 

 from the surrounding rock to the centres of intense heat. These 

 centres were surely the foci of repulsion, not of attraction ? 



There can have been no flow of water laden with iron, potash, and 

 alumina towards the heated centres, where the chlorites under con- 

 sideration were, because the author's conditions involve the fact 

 that water was driven away by the intense heat generated at those 

 centres. By what agency then, I ask, was the iron, potash, and 

 alumina divorced from their chemical combinations in other parts of 

 the rock and drawn towards the chlorites? 



The author admits that " it is natural that those who have not 

 studied the evidence furnished by the Malvern rocks should adopt 

 an old and well-known explanation of the phenomena in preference 

 to a new and seemingly improbable one " ; but surely, if Dr. 

 Callaway asks those who have not studied the Malvern rocks to 

 believe the " seemingly improbable theory " which he advocates in 

 preference to a more obvious one, it is incumbent on him to explain 

 in detail by what agency the molecular movements involved in his 

 theory were brought about. Di\ Callaway remarks that " if this 

 mineral transformation be an observed fact, it may seem unnecessary 

 to discuss theoretical objections to it"; but the conversion of 

 chlorite into biotite does not yet rank as an " observed fact." The 

 only observed fact is that chlorite and biotite have been found in the 

 same rock. Dr. Callaway offers a theory to account for this fact. 

 Those who doubt the correctness of this theory have a right to ask 

 for full proof of its genuineness before it is stamped with the Hall 

 mark. I desire to offer one more remark in conclusion. 



Dr. Callaway tells us that "the temperature of metamorphisra in 

 the Malvern rocks often rose to the point of fusion." If so, actual 

 fusion must have been the result, and biotite cannot, in those 

 localities, have been formed at the " expense of chlorite," for all the 

 chlorite wonld have been melted down and would have been merged 

 in the fused and fluid magma. If, on cooling, biotite crystallized out 

 of this magma it would have been at the " expense " of the general 



DECADE IV. — VOL. I. — NO. III. 8 



