146 Scientific Intelligence. 



becomes deep indigo-blue ; it shows no signs of freezing at — 81°, 

 but in liquid air it forms very deep blue crystals. — Jour. Ghent. 

 Soc, xci, 1862, Nov. 190V. h. l. w. 



3. Atomic Weight of Tellurium. — Much work has been done in 

 recent years upon tellurium on account of the fact that its atomic 

 weight, being higher than that of iodine, does not properly place 

 it in Mendeleeff's periodic system. All attempts to find a sus- 

 pected impurity in the element which would account for this 

 high atomic weight have been fruitless. Baker and Bennett 

 have recently given an account of some thirteen years of work 

 upon this problem, and their extensive investigations confirm the 

 conclusion that the atomic weight of tellurium is 127*60, and that 

 many methods of fractionation give no indication of the presence 

 of an unknown element. They have made the further new obser- 

 vation that highly purified tellurium does not burn in perfectly 

 dry oxygen. — Jour. Chem. Soc, xci, 1849, Nov. 1907. 



4. A JVeio Element, Lutecium. — By means of a long series of 

 fractional recrystalhzations of the nitrate of Marignac's ytterbium, 

 using nitric acid of density 1*3 as a solvent, G. Urbain has 

 succeeded in separating the material into two distinct substances, 

 one of which gives a characteristic spark spectrum. This new 

 element he calls lutecium, Lu, from an ancient name for Paris, and 

 he finds that its atomic weight is not much greater than 174. 

 The other element present he calls neo-ytterbium, Ny, in order 

 that it may not be confused with Marignac's ytterbium. Its 

 atomic weight cannot differ much from 170. Two spectrum 

 bands obtained by Lecoq de Boisbaudran's method are probably 

 characteristic of neo-ytterbium, while a third band appears to 

 belong to lutecium. — Comptes Hendus, cxiv, 759. h. l. w. 



5. The Association of Helium and Thorium. — Strutt believes 

 that he has found a case where BoltwoOd's opinion that helium 

 in radio-active minerals may be always attributed to the action 

 of the uranium-radium series of transformations is untenable. 

 He has examined a mineral from Ivitgut, Greenland, similar in 

 some respects to fluor spar, but containing rare earths, and liber- 

 ating 27 cc of helium per kilogram when heated. He finds that 

 this mineral contains no more radium than is present in average 

 rocks, .while on the other hand it gives an abundant thorium 

 emanation. He believes, therefore, that the helium has been pro- 

 duced in connection with thorium. — Chem. News, xciv, 259. 



h. l. w. 



6. Organic Chemistry for Advanced Students; by Julius B. 

 Cohen. 8vo, pp. 632. London, 1907, Edward Arnold ; New 

 York, Longmans, Green & Co. — This book contains a series of 

 essays upon important topics of organic chemistry. They have 

 been prepared from notes of lectures delivered to senior students, 

 and are intended only for those who have completed an elemen- 

 tary course of organic chemistry. The subject is presented 

 somewhat in the manner in which it has naturally developed. 

 The fourteen chapters of the book have the following titles : 



