1887.] NEW YORK ACADEMY OF SCIENCES. 135 



The chief interest in these laws is their bearing upon established be- 

 liefs as to these bodies, and the clew whicli they give, if not to all nuta- 

 tion, at least to that secular change spoken of above. 



Dr. Warring presented photographs of the tracings or auto- 

 graph of a top, with written description?. 



April 18, 1887. 



Stated Meeting. 



The President, Dr. J. S. Newberry, in the chair. 



Eleven persons present. 



Dr. J. J. Friedrich exhibited serpentine from Fifty-seventh 

 Street and First Avenue. 



The President read a list of accessions to the Library. 



Dr. Alexis A. Julien read a paper : 



the transformations of iron disulphide. 



(Illustrated with specimens.) 



(Published in the Annals, Vol. IV.) 



April 25, 1887. 

 Stated Meeting. 

 The President, Dr. J. S. Newberry, in the chair. 



A large audience present in the East Lecture Koom of the 

 Library Building, Columbia College. 



The fourth lecture of the Popular Lecture Course was deliv- 

 ered by Dr. Charles S. Minot, on 



the evolution of the head. 



(Illustrated with lantern views.) 



