66 



EXPERIJfENTS WITH IONIZED AIR. 



The curves, figure 3, contain all the data iu hand, the different series of 

 observations being distinguished by lines in different positions. Each seiies con- 

 forms pretty closely to a straight line, but these lines differ in iiidination for the dif- 

 ferent series. The colors cori'es[»ouding to the observations are also added in a 

 suggestive way. Their real positions are not the same in all series, electrically, but 

 they are so voluuietrically. 



The two most nearly satisfactory series of observations are given in the chart, 

 figure 4. The curve is iu both instances clearly linear. It is noteworthy that the 

 colore I'eferred to volumes of charged air per minute (abscissas, V) are again in 

 agreement, whereas the electrometer data referred to the same color ' differ. Some 



Fig. 4. — Simultaneous Coulombs per Second (Radially) and Volumes of the Saturated Phosphorus 

 e.manation per mlnute (longitudinally) traversing the condenser. 



variation of the constant of the electrometer, if in question, would have shown 

 itself in the initial potentials ; but these (about 40 volts) are nearly constant. 



6. Working Itypotliesia. — 1 sliall next endeavor to account in some theoretical 

 way for the observations just described, seeing that the data as a whole are very 

 satisfactory when the inherent difficulties (fluctuating ionizer, color criteria, etc., as 

 repeatedly detailed) are taken into consideration. The method pursued will be 

 alike in principle to that already applied to tubes in the ab.sence of an electric field 

 in Chapter III. The complete equation is to be deduced and the numerical reason- 

 ableness is then to be tested when the decay of the ions within the ionized region 

 is ignored. 



Let h be the absorption velocity, so that hi particles are absorbed per second 

 per square centini. by any Ijarrier, n being the number of particles })er cubic 

 centim. As usual if but 1/.3 of the particles travel in anj' given cardinal direction, 

 h is to be leplaced by 3l\ Let h'lv particles decay within a cubic centimeter per 



' Elsewhere I shall show that the degree of desiccation of the phosphorus nucleus will account 

 for the difference of slope. 



