86 EXPLOSION BY INFLUENCE. 



arsenic, as a tube does which is filled with the same gas and 

 which has not undergone any vibration. This gas reduces itself 

 into its elements, liberating, according to Ogier, + 36,700 cal., 

 which explains its instability. We see, therefore, that it is not 

 increased by the sonorous vibrations. 



5. Ethylene and Sulphuric Acid. The author endeavoured to 

 accelerate the slow combination of these two bodies, which is so 

 easily effected under the influence of continuous agitation and by 

 the concurrence of shocks produced by a mass of mercury, by 

 having recourse to the vibratory movement. This slow com- 

 bination is exothermal. 



A bottle of 240 c.c. containing pure ethylene, and also 5 

 c.c. to 6 c.c. of sulphuric acid and mercury, has been set in 

 vibration by a tuning fork (100 vibrations per second) ; the acid 

 vibrated and was pulverised on the surface ; yet at the end of 

 half an hour the absorption of gas was slight, and very nearly 

 the same as in a similar bottle kept immovable in a distant room. 



6. Oxygenated Water. 10 cc. of a solution containing 

 9 '3 mgrms. of active oxygen, placed in a bottle of 250 c.c. 

 capacity, are not altered in degree by the effect of the movement 

 of the tuning fork (100 vibrations per second) kept up for half 

 an hour. Yet the liquid actually vibrated and lost 0'9 mgrms. 

 of oxygen every 24 hours ; 10 c.c. of a solution containing 

 6 '3 mgrms. of active oxygen set in vibration (7200 vibrations) 

 in a tube of 4 c.c. full of air for half an hour gave afterwards 

 6*25 mgrms. 



7. Persulphuric Acid. Same results with the tuning fork 

 (100 vibrations); initial degree 13 mgrms., final degree 12'6 

 mgrms. With the tube (7200 vibrations), initial degree 3*6 

 mgrms., final degree 2*8 mgrms. The difference here appears 

 slightly to exceed the rapidity of spontaneous decomposition, 

 this rapidity being greater than with oxygenated water, but it 

 scarcely ever exceeds the limit of error. 



The results observed with these liquids merit all the more 

 attention since it has been possible to assimilate these systems 

 a priori to the liquids containing oxygen in a state of super- 

 saturated solution, a solution which agitation, and particularly a 

 vibratory movement, will reduce to its normal state. In fact, 

 the foregoing liquids will certainly hold a certain quantity of 

 oxygen in this state, as may be easily proved ; but this amount 

 of oxygen does not act either on the permanganate or on the 

 potassium iodide employed, and it should be studied apart. As 

 a matter of fact, it does not intervene here in any equilibrium 

 of dissociation capable of being influenced by the separation of 

 the oxygen and the oxygenated water. It would doubtless be 

 otherwise in a system in a state of dissociation, and the 

 equilibrium of which would be maintained by the presence of a 

 gas actually dissolved; but then it would no longer be a question 



