Geology and Mineralogy 635 



mathematically, whether the phenomena of precession afford 

 conclusive evidence as to the constitution of the interior of 

 the earth. In the former paper, General Barnard holds that 

 the phenomena of precession require a solid globe. In the 

 latter paper, he holds that the precession of a liquid would be 

 substantially the same as that of a solid globe, having be- 

 come convinced, like Lord Kelvin, of the validity of Professor 

 Simon Newcomb's criticism. 



Numerous short papers bearing upon geology and miner- 

 alogy occur in the annual Reports of the Smithsonian Insti- 

 tution and in the "Bulletins" and "Proceedings" of the 

 National Museum. Detailed comment on these papers is 

 precluded by the limits of this article, though many of them 

 have an importance disproportionate to their length. A few 

 of them are briefly mentioned. 



Joseph Le Conte's "Lectures on Coal" (Report, 1857) are 

 a model of truly popular exposition of a scientific theme. The 

 treatment of the paleontological part of the subject belongs, 

 of course, to the pre- Darwinian epoch, then near its end. 



T. S. Hunt's report "On the Chemistry of the Earth" 

 (Report, 1869) is a very compact summary of the views on 

 chemical geology, which are more fully presented in his 

 " Chemical and Geological Essays," and other writings. 



W. N. Rice gives results of studies on " The Geology of 

 Bermuda" (Bulletin, No. 25). He holds the islands to be 

 an atoll, originally formed by subsidence, in accordance with 

 the views of Darwin and Dana ; but supposes the subsidence 

 to have been interrupted by an epoch of elevation in which 

 enormous accumulations of aeolian limestone were formed. 



T. Egleston's "Catalogue of Minerals and Synonyms" 

 (Bulletin, No. 33) is an exceedingly handy little volume 

 for reference. All mineralogical names are given in alpha- 

 betical order ; while names of recognized species are distin- 



