s i'> Scu nt'ipr IntelMgi nee. 



ing. The study of the Secondary Enrichment Investigation con- 

 cerning the occurrence and alteration of ore minerals necessitated 

 the use and elaboration of these methods. The present book 

 must be considered as one of the important results of this investi- 

 gation. 



The methods used involve the observation under the micro- 

 scope l>y reflected light of polished sections of the opaque min- 

 erals. The means of identification include, first, the color of the 

 polished mineral, which is more accurately judged by comparison 

 with definite mineral standards; secondly, thehardness; and thirdly, 

 microchemical reactions through the use of various reagents. By 

 means of these tests and the use of the determinative tables given 

 in the book, it is possible to accurately determine the character of 

 a given mineral. , 



An important result of this new method of investigation has 

 been to show that opaque minerals are very liable to contain 

 impurities in greater or less amount which would entirely escape 

 detection by any ordinary methods of observation. It will be 

 necessary in the future to make such an examination of an opaque 

 mineral before analysis in order to be certain of the purity of the 

 material analyzed. A considerable number of species that have 

 been described as definite compounds have already been shown to 

 be mixtures of two or more different materials. 



It is proposed to call this new branch of mineralogical study by 

 the name " Mineralography." av. e. f. 



16. The Collection of Osteological Material from Maehu 

 Picclnt ; by George F. Eaton. Quarto, pp. 96 ; 39 pis., 50 figs., 

 2 tables, one map. Memoirs of the Connecticut Academy of 

 Arts and Sciences, New Haven. Volume V, May, 1916. — This 

 valuable report on the osteological collections made in connection 

 with the Peruvian Expedition of 1912 has been recently issued. 

 A notice will appear in a later number. 



17. The Birds of North and Middle America ; by Robert 

 Ridgway, Curator, Division of Birds. Part VII. Pp. xiii, 

 543, 24 pis. Bulletin of the IT. S. National Museum. No. 50. — 

 This extensive work on American birds was begun in 1901. The 

 seven volumes thus far published include 564 genera and 2,319 

 species and sub-species, with a considerable number of extra- 

 limital genera and species, whose characters are given in the 

 "Keys." The present volume contains the cuckoo-like birds, 

 parrots, and pigeons. Part VIII, in preparation, will include the 

 gulls and auks with their near allies. 



18. R. Comitalo Talassoc/rafico Italiana. — Notwithstanding 

 the far from quiet condition of the seas which surround Italy 

 during the past two years, the work of the Italian commission, 

 begun in 1910, still goes on uninterruptedly. Fifty-two memoirs 

 are now included in the list of publications. Recent sendings 

 include the bi-monthly bulletin for 1915 and memoirs 44-52. 

 The last-named are all on subjects in natural history except No. 

 50, which discusses the solubility of gypsum in sea water. 



