TH B 



AMERICAN JOURNAL OF SCIENCE 



[FOURTH SERIES.] 



Akt. XXX Y. — On the Effect of Temperature and of Moisture 

 on the Emanation of Phosphorus, and on a Distinction in 

 the Behavior of Nuclei and of Ions ; by C. Barus. 



Introduction. 



1. Object, etc. — Endeavoring to differentiate the properties 

 of the nucleus and the ion, it occurred to me that the effects 

 of temperature, when worked out simultaneously by the volu- 

 metric and by the electrical methods, would probably present 

 a contrast. If the two functions relating to condensation and 

 to electrical conduction are different, then their thermal varia- 

 tions are not likely to be the same. The temperature which 

 insures the maximum production does not also necessarily 

 insure maximum instability. The results of the following 

 paper bear out this surmise. 



Again, if phosphorus is to be used as an ionizer, some defi- 

 nite knowledge as to the cause of its variable intensity is essen- 

 tial from a practical point of view. The substance is so 

 remarkably adapted for the purpose in many ways, that the 

 endeavor to put it in control quantitatively is well worth while. 

 This too, I think, has been accomplished. 



Finally I have shown that the low number of ions(/i=2xl0 4 

 per cubic centimeter) in the saturated phosphorus emanation, 

 found from the experiments with the tubular condenser, is due 

 to non-saturation. I have been able to nearly double this 

 number, putting these results in accord with the data of plate 

 and spherical condensers. Incidentally certain curious condi- 

 tions under which the emanation produces permanent conduc- 

 tion in the condenser is identified with the occurrence of traces 

 of moisture. This behavior so closely resembles the effects of 

 radio-activity, that the extreme caution needed before such a 

 property can be predicated, becomes apparent. 



Am. Jour. Sci. — Fourth Series, Vol. XTI, No. 71— November, 1901. 

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