448 



Worm-shells, description of a rare spe- 

 cies of, i. 233, 334. 



Y. 



Yarrell (W.) on the change in the plu- 

 mage of hen-pheasants, ii. 317. 



Yelloly (Dr.) on the tendency to cal- 



culous diseases, and nature of uri- 

 nary concretions, ii. 359, 413. 



Young (Dr. T.) on sound and light, i. 

 8; on the mechanism of the eye, i. 

 35 ; on the theory of light and co- 

 lours, i. 63 ; on some cases of the 

 S reduction of colours, not hitherto 

 escribed, i. 92; experiments and 

 calculations relative to physical op- 

 tics, i. 131 ; on the cohesion of flu- 

 ids, i. 171 ; hydraulic investigations 

 for ascertaining the motion of the 

 blood, i. 298 ; on the functions of the 



heart and arteries, i. 314^ table of 

 elective attractions, and on the se- 

 quences of double decomposition, i. 

 325 ; remarks on the oblique riders, 

 &c. in the construction of ships, i. 

 494 ; on the probabilities of error in 

 physical observations, and on the 

 density of the earth, ii. 106 ; ex- 

 pression for the refraction of an at- 

 mosphere resembling that of the 

 earth, ii. 207 ; formula for express- 

 ing the decrement of human life, ii. 

 275. 



Z. 



Zariffa, on the stomach of the, ii. 389. 



Zeolite, on a mineral substance for- 

 mei-ly supposed to be, i. 209 ; com- 

 position of, i. 396. 



Zoophytes, experiments on, i. 25. 



THE END. 







PRINTED BY RICHARD TAYLOR, 

 KED LION COURT, FLEET STREET. 



