NATURAL SCIENCES OP PHILADELPHIA. 165 



gaseous envelope of our earth. The true explanation is this. The stars ap- 

 pear colored to the naked eye in Europe as well as in America. Astronomical 

 observers see them colored the same in all countries. But in some countries 

 their colors are slightly dimmed by the more habitual haziness of the atmo- 

 sphere, so much dimmed that they are not noticed by unprofessional gazers. 

 When these latter persons arrive in a more cloudless region, they notice the 

 colors of the stars simply because a slight veil is withdrawn, and not because 

 new colors have been added. 



The evidences of changes of color are now most abundant among the 

 double and multiple stars. This is because the colors of these have been 

 more generally recorded. Hence the importance of having records made, ag 

 frequently as possible, of the colors of all the stars, as they appear both to the 

 aided and the unaided vision. Of course no careful observer will decide on the 

 color of a star from its appearance in an unfavorable atmosphere, nor will he 

 neglect the influence of the sun and moon, nor other means for correcting 

 and confirming his observations, as presented in the rules of my last paper.* 



July bth. 

 Dr. Coates in the Chair. 

 Eight members present. , 



July 12th. 



Yice-President Bridges in the Chair. 



Eleven members present. 



A paper was offered for publication entitled " Description of a Gar- 

 Pike, supposed to be new." By Alexander Winchell. 



July 19th. 

 Vice-President Bridges in the Chair. 



Ten members present. 



A paper was offered for publication entitled " Contributions to the 

 Herpetology of Tropical America." By E. D. Cope. 



The death of Thomas Dunlap, member of the Academy, on the 11th 

 instant, was announced. 



July 2,6th. 

 Vice-President Bridges in the Chair. 

 Six members present. 



* Page 57 of this volume. 



1864.] 



