OF ARTS AND SCIENCES. 331 



Mr. N. D. C. Hodges read, by invitation, a paper on the 

 Dimensions of Molecules. 



Professor Pickering described a new form of Nebula Pho- 

 tometer. 



Professor Trowbridge read two contributions from the 

 Physical Laboratory of Harvard College, with the following 

 titles : — 



" On the Vibration of Elliptical Plates." 



" On a Method of Studying Wave Motion." 



The following papers were presented by title : — 



" Characters of New Species of Plants from Mexico, col- 

 lected by Dr. E. Palmer and Dr. C. C. Parry." By Dr. Asa 

 Gray. 



" A Revision of the North American Liliaceoe, and De- 

 scriptions of some New Species of other Orders." By Mr. 

 Sereno Watson. 



" On Complex Inorganic Acids." By Dr. Wolcott Gibbs. 



" On the Synthesis of Anthracene." By Professor C. 

 Loring Jackson and Mr. J. Fleming White. 



The meeting: then dissolved. 



