388 Scientific Intelligence. 



iodide was then heated until fused in a current of dry and pure- 

 carbon dioxide in order to drive off hydrogen iodide and mois- 

 ture ; after which the iodide was heated in a current of dry air to 

 between 220° and 240°. A continuous stream of violet vapor 

 was carried forward and condensed in beautiful crystals in the 

 cooler parts of the tube. To test the purity of the iodine so 

 obtained 2-7529 grams was placed in a tube and heated to 75° in 

 a slow current of dry air. After 4 hours only a slight brown resi- 

 due remained, weighing 0*3 milligram; this proving afterward to 

 have come from impurities in the air. No copper could be 

 detected in it by the spectroscope. The fusing point of this iodine 

 was 112-5°-114°. It is blacker than the ordinary iodine. —J. 

 Chem. Soc, lxxiii, 148-157, March, 1898. g. f. b. 



5. On the Borides of Calcium, Barium and Strontium. — An 

 investigation has been made by Moissan and Williams on the 

 preparation and properties of the borides of calcium, barium and 

 strontium. Calcium boride is readily obtained by heating in a car- 

 bon crucible a mixture of 1000 parts of calcium borate, 630 parts 

 of aluminum and 200 parts of sugar carbon, for seven minutes by 

 means of a current of 900 amperes and 45 volts. The calcium 

 borate is completely reduced by the aluminum, the carbon pre- 

 venting the formation of aluminum oxide. The product obtained 

 is broken up and treated first with dilute and then with concen- 

 trated boiling hydrochloric acid, water, ether, toluene and hydro- 

 fluoric acid. The resulting substance has the composition CaB 6 

 and forms transparent microscopic crystals, cubic or rectangular 

 in form, which scratch rock crystal and even rubies. Their 

 density at 15° is 2*33. Fluorine in the cold and chlorine at a red 

 heat attack it readily, the former with incandescence. It is not 

 decomposed by water at 250° under pressure, but the gaseous 

 hydracids attack it at a dull red heat. Barium boride prepared 

 similarly has analogous properties. Its crystals are small but 

 very regular, having a density of 4*36 at 15°. They scratch rubies 

 but not the diamond. Strontium boride is not attacked by fluo- 

 rine in the cold. Its density is 3*28 at 15°. — G. i?., cxxv, 629- 

 643, November, 1897. g. f. b. 



6. The Arrangement of Atoms in Space / by J. H. Van't 

 Hoff. 2d revised and enlarged edition. With a preface by 

 Johannes Wislicenus, and an Appendix, Stereochemistry among 

 Inorganic Substances, by Alfred Werner. Translated and edited 

 by Arnold Eiloart. 12mo, pp. xii, 212. London, 1898. (Long- 

 mans, Green & Co.) — Perhaps no book of recent times has had a 

 more profound influence upon structural chemistry than this little 

 volume. It appeared first in 1877 under the title " La Chimie 

 dansl'Espace," and had for its motto a quotation fromWislicenus's 

 paper on lactic acid, published in 1869 : " The facts compel us to 

 explain the difference between isomeric molecules possessing the 

 same structural formula? by the different arrangement of their 

 atoms in space." The new edition, of which the present work is 

 a translation, was issued in 1894, and is to a considerable extent a 



