5^2 



Wollafton, Dr. W. H. on double Im»ges 



caufed by Atmofpherical Refrailion, 



298 

 Wood, on the Light of, 455, 456 

 Wood, Foffil, found at a great Elevation, 



380 

 Wool, Projeft for extending that of Spanifli 



Sheep, &c. 289 

 Woulfe, Apparatus of, improved, 41 



t N D 



X. 



Y. 



Yellow Oxide of Mercury, how to deteft 



free Allphurkj Acid in, IGI 

 Young, Dr. on the Number of primitive 



calorific Kays in Solar Light, 385 



z. 



Zaffre, 37 



Zinc, on the PurifTcation of, 558. 



Zircon, on a new Variety of, 55S 



Printed by W. Stratford, Crown-Court, Temple-Bar. 



