652 SCIENTIFIC RECORD FOR 1885. 



could or conld not be exploded by electric sparks cannot be regarded 

 as settled ; the author thinks that such a mixture would prove to be 

 uou-explosible. He regards the mutual action of hydrogen, oxygen, 

 and water as in all respects comparable with that of carbon monoxide, 

 oxygen, and water, or with that of zinc, oxygen, and water. The changes 

 which occur in the explosion of moist hydrogen and oxygen are thus 

 formulated : 



(1) H2+2H20+02=2H20+H202 



(2) H202+H2=2H20 



The second reaction has been experimentally demonstrated by the 

 author. {Ber. d. cliem. Ges., xviii, 1890.) 



Indications of the Existence of an Allotropic Modification of Nitrogen 

 and Synthesis of Ammonia. — Under this title George Stillingfleet John- 

 son has published a pamphlet of theoretical and practical interest. He 

 reviews the experiments of Donkin, Bertbelot, D^h^raiu, and Maquenue, 

 P. and A. Thenard, and H. St. Clair Deville, showing the production of 

 ammonia and of its salts by the action of the silent discharge, or of 

 electric sparks upon mixtures of atmospheric nitrogen and oxygen, of 

 watery vapor and nitrogen gas, and of hydrogen, nitrogen, and hydro- 

 chloric acid. Mr. Johnson then repeats some of his earlier experiments 

 on the synthesis of ammonia, and after carefully eliminating sources of 

 error obtains results which lead him to infer that the gas evolved from 

 hot solutions of ammonium nitrite contains an allotropic or active form 

 of nitrogen, which differs from ordinary nitrogen in possessing the prop- 

 erty of forming ammonia by direct synthesis with hydrogen in presence 

 of heated spongy platinum, and which is converted into ordinary in- 

 active nitrogen by the action of heat, precisely as ozone is converted 

 into ordinary oxygen by the same agency. 



In experimenting with atmospheric nitrogen the author failed to ob- 

 tain ammonia by passing the nitrogen, recently heated and mixed with 

 hydrogen through red-hot tubes in the presence of platinum sponge. 

 But he did obtain ammonia from atmospheric nitrogen which had not 

 been heated. 



One of the most important experiments is thus described : Into an 

 ordinary eudiometer tube full of mercury, pure nitrogen gas, obtained 

 by any method, is introduced and measured. Next admit three times 

 its volume of pure hydrogen gas and introduce into the gaseous mixt- 

 ure a fragment of wood charcoal previously ignited in hydrogen gas, 

 or better, in a mixture of three volumes of hydrogen with one volume 

 of nitrogen gas. Now pass the spark continuously through the wires 

 of the eudiometer. About 4 to 6 c. c. of the mixture are combined and 

 absorbed by the charcoal per hour, until finally the whole of the gas 

 may be made to disappear; after which, if the charcoal be removed, it 

 will be found impregnated with ammonia. {Chem. News, lit, 34.) 



