Mixter — Partial non-explosive Combination, etc. 327 



few seconds. The gas remaining was nearly all absorbed by a 

 solution of ferrous sulphate, showing that only a small portion 

 of the nitric oxide had been decomposed. 



Experiment '6. — 50 cc of gas were condensed to 6 ec and sparked 

 a short time. After treatment with ferrous sulphate only 0*5 CC 

 remained. 



The deportment of nitrous and nitric oxide in the above 

 tests is much the same as in the well known experiments of 

 sparking these gases at ordinary pressure. 



The results of the experiments described in this article will 

 be discussed in the next paper. 





Art. XXX V. — On a Hypothesis to explain the partial non- 

 explosive Combinatio7i of Explosive Gases and Gaseous Mix- 

 tures ; by W. G-. Mixter. 



[Contributions from the Sheffield Laboratory of Yale University.] 



Much has been done in investigations of the conditions 

 under which gases combine gradually or with explosive vio- 

 lence. The velocity of explosive waves has been determined, 

 and the influences of pressure, and of excess of one gas or 

 dilution with an indifferent one, have been studied. Dixon* 

 states, " The explosive wave is propagated not only by burnt 

 molecules, but also by those of the heated but yet unburn t 

 molecules." But so far as the writer is aware, no hypothesis 

 has been advanced to account for the fact that explosive 

 mixtures -will not explode at low pressures, and that weak 

 electric sparks may not cause explosions, where strong sparks 

 do. Victor Meyer, with the aid of his pupils, has made a large 

 number of experiments with explosive mixtures at different 

 temperatures and pressures, but he has offered no explanation 

 of the phenomenon of slow combination in such mixtures. As 

 the union of hydrogen and oxygen has been more thoroughly 

 studied than that of other gases, the deportment of detonating 

 gas, by which is understood equivalent amounts of hydrogen 

 and oxygen, under various conditions, affords the best basis 

 for discussion. The behavior of certain other gases, and the 

 observations of different experimenters, will also be considered. 



Dixonf found that detonating gas at a pressure of 70 mm does 

 not explode when an electric spark is passed through it, and 



* Chem. News, lxvii, 39. f Trans. Roy. Soc., 1884, 634. 





