8o 



CONDENSATION OF VAPOR AS INDUCED BY NUCLEI AND IONS. 



gular diameter, S = 2R tan d, s = 2r sin 6, or 5 = 8.3 s/\/i s 2 /4 f2 > 

 5=0.12 5/Vi +S 2 /4^ 2 , ^ = 250 cm., r = 3o cm. Fig. 24, c, shows the 

 relation of these quantities. Since the elementary diffraction equation 

 may be put 



sin i .22 

 for the first minimum 



5 =(2. 44 R l/d)/\/i(i.22 l/d) 2 



and 5 would therefore appear to be less immediately adapted for the 

 equation than s. It does not follow, however, that this 5 and the one 

 observed at the goniometer work are the same. In fact they are not, 

 the latter being larger for reasons involved in the more recondite theory 

 of the experiment, or else due to irregular refractions at the remote 

 ends of the chamber. In practice 5 will usually be preferred to s. 



In table 35, y = .Tji = (p [dp 2 ] TT)/(/> TT) ; <W/> = 0.233; io e m = 

 3.80 at 20; therefore at 25, 10 per cent higher or io 6 m = 4.i8 grams 

 per cubic centimeter. Hence n f = 6ms s /ita? o. 244 5 3 /io 3 . The value of 



TABLE 36. New apparatus. Two coronas in contact. Bar. 76.4 cm.; temp. = 27 C; 

 S=2R tan 0; ^ = 250 cm.; cock open 5 seconds; interval i minute. o() 3 =g.g. 

 g.2. Phosphorus nuclei. of> 3 /p o . 1 20 ; ^ = 0.875; io 6 wz = 2.33; ' = 6.5. 



