284 



SCIENCE 



[N. S. Vol. XXXIV. No. 870 



n/10 to Ji/50, »/100 and ?i/500 solutions are given. 

 The values of the concentration of the ions and 

 undissociated acid as calculated from these meas- 

 urements are compared with the corresponding 

 values of concentration as calculated from con- 

 ductivity measurements. The discrepancies be- 

 tween the two methods of determining concentra- 

 tion are discussed. 



Note on the Concentration of Hydrogen Ion in 

 Sulphuric Acid: E. C. Tolman and L. H. 



GitEATHOUSE. 



The results are described of an indicator method 

 of determining the concentration of hydrogen ion 

 in sulphuric acid. A suitable indicator is added to 

 the solution of sulphuric acid in question and the 

 color compared with that of a solution of a uni- 

 univalent acid (HGl or HNO3) to which the same 

 amount of indicator has been added. By adjust- 

 ing the concentration of the uni-univalent acid the 

 concentration of a solution isohydric with the sul- 

 phuric acid can thus be found, and the concentra- 

 tion of hydrogen ion in this solution calculated 

 from conductivity measurements. 

 Estimation of Degree of Ionization in Moderately 



Concentrated Solutions of Electrolytes: E. W. 



Washburn. 

 The Dissociation Relations of Ccesium Nitrate, 



Lithium Chloride and Potassium Chloride in 



Aqueous Solution at 0° : E. W. Washbukn and 



D. A. MacInnes. 

 Diameters of Fores in Osmotic Membranes: F. E. 



Baktell. 

 Some Applications of the Electronic Conception 



of Positive and Negative Valencies: IV., Flu- 

 orescence: Harry Shipley Try. 

 Action of Zinc-copper Couple on Bromoform: 



Wilder D. Bancroft. 



Viscosity of Solutions of the Metal-ammonia 

 Salts: Arthur A. Blanchard and Harold B. 



PUSHEE. 



Ammonia when added to solutions of salts of 

 alkali and alkaline earth metals causes slightly 

 greater increase of viscosity than when added to 

 pure water. Comparing this fact with the known 

 fact that ammonia added to salts of silver, copper 

 and zinc, causes a marked decrease in viscosity,* 

 the conclusion is drawn that while the latter 

 metals form more compact complex ions with 

 ammonia than with water, the alkali and alkaline 

 earth metals form more compact complex ions 

 with water than with ammonia. 



* Blanchard, J. Am. Chem. Soc, 1904, 26, 1315. 



Some New Ammono Salts: E. C. Franklin. 



Ammonates of Barium Trinitride: A. W. Browne 



and E. A. Eekate. 



The 0° isotherm of the pressure-concentration 

 diagram for the two-component system barium 

 trinitride, ammonia, has been studied over pres- 

 sures ranging from cm. to 300 cm. Three solid 

 ammonates were obtained, of the respective com- 

 position BaNo-NHs, BaNo.2NH3 and BaNe-SNHa. 

 Under certain conditions a curious reluctance was 

 observed, especially on the part of the lower 

 ammonates, either to take up or to give up am- 

 monia. 



Ammonated Ammonium Trinitride: A New Hy- 

 dronitrogen: A. W. Browne and A. E. Houle- 



HAN. 



Pressure-concentration isotherms at — 33°, 0° 

 and 20° have been studied for the two-component 

 system hydronitric acid, ammonia, over a range of 

 pressures from cm. up to about 175 cm. At the 

 two higher temperatures no indication of the 

 formation of an ammonated ammonium salt was 

 obtained. At — 33°, however, a diammonate of 

 the formula NH4N3.2NH3, or NoHi„, was obtained. 

 This substance was obtained in the form of clear, 

 colorless, somewhat elongated plates, which at 

 — 33° are in equilibrium with solid ammonium 

 trinitride and ammonia gas at a pressure of about 

 22 cm., and with its saturated solution and am- 

 monia gas at about 42 cm. At — 33° one gram 

 of liquid ammonia dissolves one and nine tenths 

 grams of the diammonate. At 0° one gram of 

 liquid ammonia dissolves nearly one gram of the 

 "anammonous" ammonium trinitride. 



Throughout the research a specially constructed 

 glass apparatus was employed by means of which 

 it was possible accurately to measure the amounts 

 of ammonia introduced into the system or with- 

 drawn from it. 



Behavior of Certain Metals in a Liquid Ammonia 

 Solution of Ammonium Trinitride: A. E. 



HOULEHAN. 



Weighed amounts of ammonium trinitride were 

 dissolved in liquid ammonia and were brought 

 into contact, in a specially constructed nitrometer, 

 with weighed amounts, respectively, of metallic 

 lithium, sodium, potassium, magnesium, calcium, 

 line, aluminum and tin. The first five metals 

 acted vigorously, liberating hydrogen quantita- 

 tively from the hydronitric acid, and forming the 

 corresponding metallic trinitride. Zinc acted very 

 slowly, and aluminum and tin did not act at all. 



