Febeuaky 17, 1905.] 



SCIENCE. 



261 



acids, and to some extent by salts of or- 

 ganic acids. With the exception of sul- 

 phates, salts of the mineral acids in general 

 have no efifect. One part of N3 in 100,000 

 parts of solution may be detected. Trini- 

 trides must be separated from sulpho- 

 cyanates and acetates, should these be pres- 

 ent, before the addition of the ferric 

 chloride takes place. 



Hydrazine may be detected by making- 

 use of either of the following facts con- 

 cerning its inorganic salts: (1) When 

 heated with nitric acid they are oxidized, 

 yielding hydronitric acid; (2) when treated 

 with silver nitrite under proper conditions 

 they yield silver trinitride. 

 Tungsten Hexahromide: F. F. Exner. 



(Read by title.) 



Reaction between Zinc and Copper Sid- 

 phate: A. J. Hopkins. (Read by title.) 



Non-Existence of Copper Hydroxide: A. J. 

 Hopkins. (Read by title.) 



Notes on the Absorption of Hydrochloric 

 Acid as a Basis for Standard Solutions: 

 A. T. Lincoln. 



The author described a simple method, 

 in which the amount of hydrochloric acid 

 absorbed in a given quantity of water is 

 determined by Aveighing, and gave results 

 obtained by his students in using the 

 method. 



A Neiv Burette Holder: A. T. Lincoln. 



A New Method of Determining the Oxygen 



in the Air: I. W. Fay. 



The apparatus consists of a stout glass 

 tube, twenty-one inches long and an inch 

 in diameter, sealed at one end and ground 

 evenly at the other. Rods of phosphorus 

 eleven inches long and one eighth inch in 

 diameter are held in place at the closed end 

 by a perforated rubber diaphragm one 

 half inch thick. A paper scale, eight 

 inches long and divided into 200 divisions, 

 is glued to the tube so that the 200 mark is 

 at the open end. The tube is kept full of 



water when not in use. For a determina- 

 tion, pour out the water down to the zero 

 mark, close with a glass plate and invert 

 in a small vessel of water. When the 

 oxygen has been removed, replace the plate, 

 turn the tube upright and read the volume 

 of gas. Correct for the reduced tension 

 of the gas when the tube is inverted. Then 

 two divisions on the scale are equivalent 

 to one per cent, of oxygen. 



A Modified Westphal Balance for Use with 

 Solids: F. N. Williams. 



Reactions in Liquid Ammonia: E. C. 

 Franklin. 



Liquid ammonia resembles water in many 

 of its properties, such as high specific heat, 

 heat of volatilization, critical temperature 

 and pressure, and high dielectric constant. 

 Both are associated liquids, both combine 

 with many salts, and both are good ionizing 

 solvents. The reactions of acid and basic 

 amides dissolved in liquid ammonia are 

 closely analogous to the reactions between 

 bases and acids in water, as shown by the 

 general equations: 



MNH2 -j- AcNH„ = AcNHM + NH,, 



and 



2MNH, + AcNH, = AcNM^ + 2NH3. 



Reactions of the types below were also 

 studied : 



AgNOs + KNH, = AgNH, + KNO3. 



Pb ( NO3 ) 2 -f- 2KNH2 = PbNH + 2KNO3 + NH3, 



and 



Bilj + 3KNH, = BiN -f SKI + 2XH3. 



It was further shown that salts of mercury, 

 arsenic, etc., when dissolved in aimnonia 

 undergo ' ammonolysis ' in much the same 

 way that they are hydrolyzed in water. 

 A number of other points of resemblance 

 were given. The article will appear in the 

 Journal of the society. 



organic chemistry. 

 James F. Norris, chairman. 



