No. III. 



The Abstract of Sir William R. Hamilton's Memoir on 

 Quaternions, read on February 10, 1845, and referred to in 

 page 64, has not been received for insertion in this Appendix. 



Nor have the Abstracts of Sir William R. Hamilton's 

 Memoirs on the New Imaginaries, read on July 14 and 21, 

 1845, and referred to in pages 111, 112, been received. 



