424 Revieics — Smithsonian Institution, Washington — 



gold, and tlie alloys of each. Next the variations in composition 

 are considered, and the relation of water to composition and to 

 physical properties ; then tlie relation of composition to physical 

 properties, such as density, magnetism, and lustre. 



Physical mineralogy is next treated of, and we have a brief essay 

 on the crystal, on crystallographic axes, on crystal form and 

 crystal systems, etc. ; characters relating to cohesion and elasticity, 

 characters depending upon mass or volume ; properties relating to 

 heat, magnetism, and electricity ; optical characters depending 

 upon the action of light, etc., and characters depending upon the 

 action of the senses, as touch, taste, odour ; and lastly, on resistance 

 to chemical action. 



(F) By an accident of arrangement, Mr. Wirt Tassin's second 

 part, " Classification of the Mineral Collections in the U.S. National 

 Museum," has been separated by the interpolation of two other 

 essays (D and E) : we will, however, notice this part (F) next to 

 part C. Classification 1, Elements. Of the seventy or more 

 elements at present known to chemistry, but eighteen, excluding 

 those occurring only in the gaseous state, are found native. With 

 the native elements are included the native alloys, or compounds 

 and mixtures of elements belonging to the same groups in the 

 periodic system. 



A list of these native elements is then given, with their native 

 alloys and compounds, in groups, as (1) diamond, bort, carbonado, 

 graphite, schungite, graphitoid, cliftonite ; (2) sulphur (and its 

 compounds), selenium, tellurium, etc.; (3) arsenic, etc., antimony, 

 bismuth ; (4) tin, lead ; (5) iron, catarinite, etc. ; (6) platinum, 

 platiridium, iridium, osmiridium, palladium, etc. ; (7) mercury, 

 amalgam, copper, silver, gold, electrum, porpezite, rhodite. 



These are followed by compounds of the elements, as (A) compounds 

 of halogens-fluorine, chlorine, bromine, and iodine ; (B) compounds 

 of sulphur, selenium, and tellurium, also arsenic, antimony, bismuth, 

 and germanium ; (C) oxygen compounds ; (D) compounds of organic 

 origin (as mineral wax, fossil resins), asphaltum, mineral oils, coals, 

 etc., and the salts of the organic acids, oxalates, and mellates. 

 A full index of minerals is given at the end. 



These papers by Mr. Wirt Tassin are likely to prove useful to the 

 curators of minerals in other museums seeking a plan of arrangement 

 for their collection. We can also strongly recommend (1) the 

 admirable Introduction to the Study of Minerals, by L. Fletcher 

 (price 3d.), British Museum (Natural History), with a guide to 

 the Mineral Gallery (pp. 120, 8vo) ; (2) Introduction to a Study of 

 Meteorites, by L. Fletcher (price Sd., pp. 92, 8vo) ; (3) Introduction 

 to a Study of Eocks, by L. Fletcher (price Qd.), British Museum 

 (Natural History), (pp. 118, 8vo). 



(D) Mr. George H. Cooke, surgeon, U.S. Navy, supplies us 

 with an interesting account of Easter Island in the South Pacific 

 Ocean. The U.S. steamer "Mohican" sailed from Callao, Peru, 

 March 6th, 1868 (? 1886), under orders for a protracted cruise, on 

 special duty, among the islands of the South Pacific, with instructions 



