350 



SCIENCE 



[N. S. Vol. XXXIV. No. 872 



aplite and myrmecite are considered. It is 

 not possible within the limits of this brief 

 notice to do more than draw attention to the 

 eosmographical significance attributed to the 

 granites by Professor Tchirwinsky and his 

 opinion of the place they occupy in the earth's 

 crust (pp. 645-654). He believes that gran- 

 ite is only to be found in the outermost part 

 of the crust, and that it plays a very small 

 part in the upbuilding of our planet. This 

 conclusion is drawn from the relation of the 

 mean specific gravity of granite to that of the 

 earth. The average specific gravity of the 

 basic eruptive rocks, according to figures for 

 gabbro, diabase, basalt and diorite, as given 

 by Osann, is about 2.9; that of granite is 

 from 2.67 to 2.68 (p. 636). Now it is com- 

 puted that the specific gravity of the earth's 

 crust to a depth of 4,000 meters only is on the 

 average 3.13. This would indicate that the 

 granite formations are comparatively super- 

 ficial. In this connection it is interesting to 

 note that the mean specific gravity of the 

 moon, which Professor Tchirwinsky terms 

 " the sister or the daughter of the earth," and 

 that of the meteorites, is from 3.4 to 3.5. 

 Much importance is based upon the absence 

 of magnesia, and the associated biotite; the 

 latter is only of rare occurrence and magnesia 

 is one of the least plentiful of the constituents 

 so that it could be questioned whether its 

 presence is of much or any importance. 



There are three things to be regarded in a 

 volume of such magnitude as the work of 

 Professor Tchirwinsky. We regret that a 

 communication of such value as he sets forth 

 in his work should be published only in the 

 Russian language, an unfortunate circum- 

 stance for most workers who understand only 

 English, German or French. 



Second, many of the analyses quoted are 

 old ones; the more recent ones by American 

 analysts having been omitted. This is re- 

 grettable since they would have greatly in- 

 creased the value of the deductions. 



Nevertheless the work is a monument of 

 great value and as a contribution to petrology, 

 of great importance. 



George Frederick Kunz 



De Eietsuiherindustrie in de Verschillende 

 Landen van Productie. H. C. Prinsen 

 Geerligs. Pp. xviii + 416 ■+ xxiii. Am- 

 sterdam, J. H. De Bussy. 1911. 

 This is the fourth volume of a hand-book of 

 sugar-cane culture and cane-sugar manufac- 

 ture, published by the lavanese sugar-experi- 

 ment stations, a work of great value and 

 importance for the sugar industry. 



The author first gives a concise historical 

 review of the sugar industry from the earliest 

 times and then passes on to describe in detail 

 the cane industry of all countries — some forty- 

 odd in number — at the present time. 



Prinsen Geerligs considers his theme from 

 the historical, the technical and the economic 

 point of view; he enters into the geographical 

 and the climatic conditions of each country, 

 discusses the technical evolution of the in- 

 dustry, studies the bounty question, and gives 

 copious data on the consumption and export 

 of sugar in the several countries. 



A number of charts, diagrams and maps, as 

 well as sundry illustrations, scattered through- 

 out the book, add greatly to the elucidation of 

 the immense amount of material brought to- 

 gether within these pages, material nowhere 

 else available in so convenient a form. 



Issue of a publication of this kind, a publi- 

 cation of importance to workers in many sec- 

 tions of the globe, causes one to voice regret 

 that it should have appeared in Dutch, a lan- 

 guage known to but comparatively few. 

 There certainly is need of a true world lan- 

 guage in which all works of great and general 

 interest should be published and thus prove 

 accessible to all without expenditure of the 

 additional labor of translation and loss of 

 time. 



It is to be hoped that this book may soon 

 appear in one or more of the leading tongues 

 — an English version, certainly, would be sure 

 of a warm welcome. E. G. Wiechmann 



The Reduction of Domestic Mosquitoes: In- 

 structions for the Use of Municipalities, 

 Town Councils, Health Officers, Sanitary 

 Inspectors and Residents in Warm Climates. 

 By Edward Halfoed Eoss, M.E.C.S. Eng- 



