518 



curious applications of his instrument to the obtaining of qualitative 

 results, having applied it to show the concentration of the solution 

 of an iron salt produced by the attraction of a magnet, the state of 

 a solution about a growing crystal, &c. The use of the instrument 

 is, however, by no means confined to qualitative observations ; and 

 in two memoirs published last year in the 'Annales de Chimie,' the 

 author has successfully determined by its means the refracting 

 power of the vapour of water, and the influence of even a mode- 

 rate pressure in altering the refractive power of water in the liquid 

 state. 



MONS. JAMIN, 



Accept this token of the great value which we attach to your ex- 

 tensive series of experimental researches on Light. 



A Royal Medal has been awarded to Mr. Albany Hancock for 

 his numerous and varied contributions to Comparative Anatomy and 

 Physiology, but more especially for his " Researches on the Organ- 

 ization of the Brachiopoda" which will appear in full in the forth- 

 coming volume of the ' Philosophical Transactions.' 



Many of Mr. Hancock's labours having been carried on conjointly 

 with his friends Dr. Embleton and Mr. Alder, it is proper on this 

 occasion that their merits should be duly acknowledged. 



Of these conjoint papers may be more particularly noticed those 

 upon the organization of Eolis and Doris, which are remarkable not 

 only for the clear exposition they give of the previously much mis- 

 understood structure of the genera in question, but are also import- 

 ant for the new and enlarged views they contain respecting many 

 points in the economy of the Mollusca. 



Together with these must also be mentioned the well-known 

 ' Monograph on the British Nudibranchiate Mollusca,' in which Mr. 

 Hancock was associated with Mr. Alder, a work eminent alike for 

 the beauty and fidelity of its illustrations, and the value and com- 

 pleteness of its zoological and anatomical details. 



Among the more important of Mr. Hancock's numerous inde- 

 pendent contributions to science, should be noticed a valuable paper 

 on the "Excavating Powers of certain Sponges;" his discovery and 

 accurate account of a new and curious genus of burrowing Cirripeds; 





