NUCLEI IN STRONG ODORS. 



121 



Table 47. Miscellaneous experiments. Water nuclei effect of metal surfaces, of odors, 

 etc. dp =p - p 3 . Four-inch pipes and plug cock. 



Date, etc. 



May 5. Wet cloth lining in exhaust tube . 



May 6 



May 6 



May 7 



Examination of odors: 3 



May 8. Air only 



May 9. Air, camphor in 



May 10. Camphor 



May 1 1 . Camphor 



Air without camphor 



May 12. Air 



May 13. Turpentine 



May 15. Naphthalene 4 



1 Foreign nuclei not absent in second exhaustion. 



2 Hole drilled in bottom of glass fog chamber, closed by rubber cork. 



3 Apparatus blurred. 



4 Enlargement of coronas due to second (smaller) exhaustions. 



exhaust pipes were cloth-lined and the cloth kept wet to guard against 

 minor saturation error. On May 8, with the introduction of camphor, 

 the nucleation apparently rises to a maximum (g-b-p. corona); but 

 the same result is maintained after the removal of the camphor and the 

 gauze (tested in many observations not recorded in the tables). Hence 

 the camphor nuclei can not be larger than the colloidal nuclei of air- 

 water; for the presence or absence of camphor within a fog chamber is 

 inappreciable. The same conclusion follows from the experiments with 

 turpentine (where the walls of the fog chamber were speedily blurred 

 from distillation of small quantities out of the lamp wick holding the 

 liquid) and from naphthalene. It is fair to conclude that presumably 

 large molecules are nevertheless bodies of an inferior order of size rela- 

 tive to the colloidal nuclei of dust-free air. 



84. Summary. Media of coal gas and water require higher exhaustion 

 than media of air and water, media of carbon dioxide and water higher 

 than coal gas and water, to precipitate condensation in like degree, 



