156 Scientific Intelligence, 



by means of hot water gave a product which showed a lower atomic 

 w T eight for tellurium than the one usually accepted. In fact an 

 atomic weight as low as 124*32 was obtained by Flint from such 

 fractionated material in one case, in place of the usual atomic 

 weight, 127 # 5. Since Baker and Bennett had previously failed 

 to find any change in tellurium by this same method, as well as 

 by six other methods, Harcourt and Baker have repeated the 

 work. Starting with some very pure telluric acid, they made four 

 fractional precipitations in series from solutions of the tetrachlo- 

 ride by pouring them into boiling water. The tellurium of the 

 final product was carefully purified and its atomic weight was 

 determined by converting it into the tetrabromide. Five results 

 gave the numbers 127-55, 127*55, 127*53, 127*53, and 127*53, while 

 determinations on material similarly purified, but without the 

 attempted fractionation, gave a mean result of 127*53. Since the 

 results showed no evidence of the slightest change by means of 

 the fractional precipitation, the operation was not carried further. 

 The authors believe that the low results previously mentioned 

 were due to contamination of the dioxide with trioxide, which 

 was shown to give a precipitate with an orange color. It is evi- 

 dent, at all events, that no fractionation of tellurium into dif- 

 ferent elements has as yet been effected. — Chem. News, civ, 260. 



h. l. w. 



3. A New Quantitative Separation of Iron from Manganese. — 

 J. A. Sanchez has found that when pyridine is added to a neu- 

 tral or slightly acid solution of ferric and manganous salts, all the 

 iron is precipitated as hydroxide, while the manganese remains in 

 solution. It is stated that in this way it is possible to separate 

 0*0005 g. of manganese from 1 g. of iron. Neutralization of nearly 

 all the free acid by caustic soda or potash, adding pyridine, boil- 

 ing for 10 minutes, and washing the precipitate first with hot 

 water saturated with pyridine, then with hot water alone, are 

 recommended. No test analyses are given, nor is any statement 

 made in regard to the behavior of nickel and cobalt in the sepa- 

 ration, but it is stated that zinc goes partly into the precipitate 

 and partly into solution. — Bulletin, ix, 8S0. h. l. w. 



4. Famous Chemists; by E. Roberts. 12mo, pp. 247. Lon- 

 don and New York, 1911 (The Macmillan Company). — The object 

 of this little book is to give an account of the chief work of the 

 most famous chemists, and to indicate briefly the part played by each 

 in the development of the science. The subjects treated are Stahl, 

 Boyle, Black, Cavendish, Priestly, Scheele, Lavoisier, Berthollet, 

 Dalton, Davy, Gay-Lussac, Berzelius, Faraday, Dumas, Wohler, 

 Liebig, Graham, Bunsen, Hofmann, Pasteur, Williamson, Frank- 

 land, Kekule, Mendeleeff, Perkin, and Victor Meyer. The 

 essays include the important biographical facts as well as the 

 principal achievements of these heroes of chemistry. The arti- 

 cles are clear, concise, and well written, and the book will 

 be very useful to those who wish to obtain an outline of the 

 development of modern chemistry. h. l. w. 



