October 7, 1910] 



SCIENCE 



483 



traced tkroughout their full length and the in- 

 variant point found when both potassium iodide 

 and iodine existed together as solid phases in 

 presence of their mutually saturated solutions. 

 The curve was traced for both 60 and 40 per cent, 

 alcohol. 



The Solubility of Barium Nitrate in Solutions of 

 Barium, Hydroxide: C. L. Pabsons and H. P. 



COBSON. 



The solubility curves were traced for barium 

 nitrate in all concentrations of barium hydroxide 

 and likewise for barium hydroxide in all concen- 

 trations of barium nitrate. The solubility of each 

 was shown to he increased by the presence of the 

 other. It was also shown that no solid basic 

 nitrate of barium can exist at 25°. 

 The Solubility of Strontium Nitrate in Solutions 



of Strontium Hydroxide: C. L. Pabsons and 



C. L. Peekins. 



Strontium nitrate and hydroxide were found 

 to be strictly analogous to barium as described 

 in preceding abstract. 

 Basic Nitrates of Yttrium.: Chas. James and L. 



A. Pbatt. 



Equilibrium experiments show that only one 

 basic nitrate of yttrium exists, viz., 3Y.05-4N20i. 

 2OH2O. The solubility curves are also shown. 

 Comparative Analyses of Water from Great Salt 



Lake: W. C. EsAtrGH and Wallace Macfae- 



LANE. 



From 1900 until 1904 fears were expressed that 

 the Great Salt Lake was doomed to extinction, 

 as a continuous recession of the shore line took 

 place. Since that time there has been a rise in 

 the level of the lake and during the year just 

 ended new fears have arisen — fears that large 

 engineering works like the Lucin cut off of the 

 Southern Pacific and the roadbed of the Western 

 Pacific Railroad would have to be abandoned. 

 A succession of years with abnormally high rain- 

 fall is responsible for the condition now existing. 

 Analyses of the water since 1850 are collated 

 and many new analyses given. These show the 

 density to have been as low as 1.102 in 1873 and 

 as high as 1.2206 in 1903; total solids varying 

 from 13.42 per cent, to 27.72 per cent. The fig- 

 ures for February, 1910, being specific gravity 

 1.1331 and total solids 17.681 per cent. Complete 

 analyses of the water for the years 1003, 1904, 

 1907, 1909 and 1910 are also reported. 

 Improvements in Molecular Weight Determina- 

 tions by the Boiling Point Method: L. P. 

 Shtplet and J. O. Zieboltz. 



The thermometer is placed above the liquid and 

 the boiling of the latter is made to pump a por- 

 tion of it over the bulb in a thin film analogous to 

 the reflux current in the ordinary arrangement for 

 determining boiling points of pure liquids. Errors 

 from superheating are thus practically eliminated 

 and steadiness of thermometer readings increased 

 ai least tenfold besides simplifying the apparatus 

 now in general use. 



Interrelations of the Carbide and Nitride of Mag- 

 nesium: F. G. Cotteell. 



A mixture of anhydrous liquid ammonia and 

 acetylene at room temperature attacks metallic 

 magnesium rapidly, forming clear colorless tetra- 

 hedra of MgC»-C2Hi..5NH3, which lose one and 

 a half molecules of ammonia sharply at 2° C 

 and atmospheric pressure. Above 60° C. they give 

 ofl' a mixture of acetylene and ammonia, leaving 

 a little carbide and much nitride of magnesium. 

 At low temperature in vacuo, on the other hand, 

 the essentially pure carbide, previously unknown, 

 may be obtained. The carbide, a white powder, 

 begins to decompose into its elements at 425 to 

 450° C. Metallic magnesium dissolves slightly in 

 liquid ammonia with faint blue color, and even 

 at room temperature slowly forms the amide and 

 hydrogen. 



Apparatus for Determining Vapor Pressures of 



Slightly Volatile Solids: H. V. Welch. 



The method depends upon determining the 



amount of material carried off in a known volume 



of air or other gas passed through a tube of the 



solid in a thermostat. The latter is of the boiling 



liquid type, temperature regulation being effected 



through automatic electrical control of a valve 



leading to a vacuum pump. Arsenic trioxide and 



similar solids are being investigated at present. 



Preparation of Pure Anhydrous Ethyl Alcohol: 



E. C. McKelvt. 



The demand for alcoholometric density tables 

 of greater precision than the various discordant 

 ones in use at present has led to the repetition 

 at the bureau of standards of the experimental 

 work upon which such tables are based. Absolute 

 alcohol was prepared by using several different 

 dehydrating agents including lime, calcium and 

 aluminium amalgam. The density results ob- 

 tained were very concordant and point to a value 

 for the density of 0.78500 ± 0.00001 at 25°/4° 

 which is slightly lower than Jlendeleefs corrected 

 value. Acetaldehyde was found to increase the 

 density while ethyl ether and dissolved air had 

 the opposite effect. 



