CONTENTS. 
VII. Supplement to the First and Second Part of the Paper 
of Experiments, for Investigating the Cause of Coloured Con- 
centric Rings between Object Glasses, and other Appearances 
of a similar Nature. By William Herschel, LL. D. F.R. S. 
p. 149 
VIII. On the Parts of Trees primarily impaired by Age. In a 
Letter from T. A. Knight, Esq. F.R.S. to the Rt. Hon. Sir 
Joseph Banks, Bart. K.B. P.R.S. p. 178 
IX. On the Gizzards of Grazing Birds . By Everard Home, 
Esq. F.R.S. p. 184 
X. Observations on Atmospherical Refraction as it affects astro- 
nomical Observations ; in a Letter from S. Groombridge, Esq. 
to the Rev. Nevil Maskelyne, D. D. F. R. S. Astronomer 
Royal. Communicated by the Astronomer Royal. p. 190 
XL Extract of a Letter from the Rev. John Brinkley, D. D. 
F. R. S. Andrews Professor of Astronomy in the University of 
Lublin, to the Rev. Nevil Maskelyne, D. D. F. R. S. Astro- 
nomer Royal, on the annual Parallax of ot. Lyra. p. 204 
XII. On the Mode of breeding of the Oviviviparous Shark , and on 
the Aeration of the feet al Blood in different Classes of Animals. 
By Everard Home, Esq. F. R. S. p. 205 
