28 



SCIENCE. 



[N. S. Vol. XVII. No. 418. 



potassium, lithium and barium (M'H.LajOu). 

 Two methods were used-^fusion of lanthanum 

 oxide with alkaline carbonates, and prolonged 

 digestion in a very concentrated solution of 

 the alkaline hydroxides at 100° C. 



' Studies in Nitrification,' by G. S. Fraps. 



The nitrification of ammonium sulphate or 

 cotton-seed meal in a soil under constant 

 conditions is periodic, reaching a maximum 

 and then decreasing, due probably to the varia- 

 tion in the activity of the nitrifying organisms 

 at different times. A sterilized soil, inoculated 

 with different nitrifying soils, nitrifies cotton- 

 seed meal and ammonium sulphate in different 

 ratios, according to the soil used for inocula- 

 tion, due to difference in the nitrifying organ- 

 isms. A method is given for comparing the 

 nitrifying power of two or more soils. 



* Improved Method for Halogen Determina- 

 tions in Atomic Weight Work,' by Chas. 

 Baskerville and K. O. E. Davis. 



The method reported was devised in the 

 progress of the work on the redetermination 

 of the atomic weight of thorium. The nu- 

 merous precautions for the determination of 

 chlorine were rehearsed, and attention directed 

 to the deliquescence of thorium tetrachloride 

 and the difficulty incident to complete elimina- 

 tion of chlorine from the dioxidein obtaining 

 the ratio between the halogen and oxygen 

 compounds of that heavy metal. A series of 

 twenty-five preliminary determinations was 

 made of the solubility of silver chloride in 

 pure alcohol, alcoholic solution of silver 

 nitrate, and nitric acid of variable strengths 

 at different temperatures with a time variant. 

 All reagents were the so-called chemically 

 pure. 



Elevation of temperature (50° C. and 

 above), excess silver nitrate (more than 

 twenty per cent.), marked acidity (over three 

 per cent.) and prolongation of time of reac- 

 tion (fifteen minutes) were determined as 

 factors causing a result too high by from .7 

 to 4.3 per cent, (in exaggerated cases) when 

 a standard sodium-chloride solution was pre- 

 cipitated by a standard silver nitrate. This 

 was due to the formation of aldehyde from 

 oxidation of the alcohol by the nitric acid and 



silver nitrate, with consequent precipitation of 

 metallic silver with the silver chloride. Ex- 

 perimental proof of this was given. 



A new series of six determinations, where 

 all reagents were repurified, silver nitrate be- 

 ing made from metal prepared by the method 

 of Stas, was carried out. Results were ob- 

 tained giving an error of from zero to .098 

 per cent., hence it appears that the halogen 

 may be determined accurately when an excess 

 of silver nitrate is used (even to ten per 

 cent.) the solution is slightly acid (nitric), 

 the precipitation being caused at ordinary 

 temperatures with vigorous stirring for five 

 minutes in ethyl alcohol. Proper precau- 

 tions as to purification of asbestos, using 

 counterpoise crucibles, dark chamber for pre- 

 cipitation and filtration, dark bath for dry- 

 ing, etc. 



The use of alcohol appears to be new. 



' Chlorides in Tobacco,' by W. H. Pegram. 

 The work set forth in this paper was designed 

 and is being prosecuted for the purpose of 

 ascertaining whether there is a relation be- 

 tween the chlorides in tobacco and the 

 chlorides in the fertilizer used in its produc- 

 tion; also whether a high percentage of 

 chlorides (as calcium and magnesium chlor- 

 ides) affects the hygroscopic property of 

 tobacco, giving abnormal and damaging re- 

 sults at certain stages of its preparation and 

 manufacture. The data are insufficient as 

 yet to justify a valid conclusion. 



' Suggested Changes in the Law of Dulong 

 and Petit,' by J. E. Mills. Abstract has ap- 

 peared in the proceedings of the Elisha Mitch- 

 ell Scientific Society. (See Scienck, N. S. 

 Vol. XVI., No. 414, p. 907.) 



' Neodymates,' by Charles BaskerviUe and 

 W. O. Heard. 



The following methods were used in efforts 

 to prepare neodymates : Fusion with alkaline 

 carbonates, alkaline earth carbonates and 

 oxides, chlorides, digestion in concentrated 

 alkaline hydroxide solutions, and fusion with 

 sodium dioxide. Results not altogether satis- 

 factory were obtained, with the surprising ex- 

 ception of a barium compound, 



BaC03.Ba(NdO,),.5H,0. 



