EXPERIMENTS WITH IONIZED AIR. 59 



TA1U,E 13.— PROMISCUOUS RESULTS WITH BARRIERS. 



IONIZATION IN OTHER BUST PRODUCERS. 



18. Concentrated sidphunc acid.— In conclusion I will briefly advert to a few 

 endeavors to detect ionization in other dust producers. The method consists in 

 blowing dust-laden air between the plates of the condensers, the current entering 

 the center of the earthed plate and escaping at the edges. Thus 86,000 cubic 

 centims of air, bubbled through concentrated sulphuric acid in about 6 minutes, 

 produced an electric leakage equivalent to but e' = .0005, while the leakage of the 

 condenser before the experiment was d = .0010. Hence the effect is increased 

 insulation to the exclusion of all ionization. The same air current tested in the 

 color ttibe gave an intensely opa.pie field, showing a condensation producing potency 



of high order. , • ,-i 



19 Ammondc polysulphide. - Ammomc polysulphide tested m like manner 



-ave similarly negative results. About 80,000 cubic centims., passed in five minutes 

 through the condenser, showed no leakage whatever, whereas the insulation leakage 

 was originally ecpiivalent to c' = .000(3. In this case, however, the cun-ent pro- 

 duced only just perceptible darkening of the field of the color tube, evidencing 

 therefore but slight tendency to produce condensation. The effect of this reagent 

 on the color tube is in general very fleeting. When evaporating from the stopper 

 of a bottle it is very active, but only momentarily, as a rule. If, however the 

 current of air is replaced by a current of coal gas (which is itself somewhat dust- 

 laden, as appears when the test is made with the color tube), the effect is much 

 more persistent. Indeed if the air of a large room is rendered imp.ire m this way, 

 it reacts on the color tube for a longer interval than under any easdy producible 

 conditions which I have found. The fleeting nuclei from ammonm.n polysulphule 

 seem therefore much ntore stable when preserved out of contact with a.i oxydizmg 

 medium like air, and the same is true of sulphuric acid in a measure and or sulphur 

 itself. The data follow in table U. It should be noted that coal gas bearmg the 

 very active nuclei is just as inactive electrically as air 



' Increasing c' to .oio. 



' No effect. 



