aenth.] 



216 



[July 17, 



RIINFALL AT "HUSBAND'S," BARBADOES. 



REPLY TO DR. T. STERRY HUNT. 

 By F. a. Genth. 



{Bead before the American Philosophical Society, July 17, 1874.) 

 Dr. T. Sterry Hunt lias published in the Proceedings of the Boston 

 Society of Natural History, Vol. XVI., March 4th, 1874, an article, enti- 

 tled : " On Br. Ge7ith^s Researches on Corundum and its associated mm- 

 erals" in which he charges me — in common with many others — of having 

 fallen into errors and of having been led to conclusions tcholly untenable, 

 for a lack of a clear understanding as to replacement, alteration and asso- 

 ciation in the mineral kingdom. 



He then gives an outline of the manner in which the various alterations 

 in a mineral species may take place, by replacement, envelopment and 

 epigenesis with examples for each, and dwells at more length upon the 

 fallacy of considering the alterations of many minerals and rock masses 

 as the result of an epigenic process ; a doctrine which has been embodied in 

 the dictum of Prof. Dana : " regional metamorphism is pseudomorphism 

 on a broad scale.' ^ 



He then refers briefly to the results of my investigation on corundum, 

 in which I have shown that by "epigenic" pseudomorphism this min- 

 eral has been altered into numerous more complex species and rock 

 masses— and winds up by stating that he not only has carefully studied 



