CONTENTS 
OF 
No. IX. 
I* age 
A I s On the Connexion between the Optical Structure and 
Chemical Composition of Minerals, By David 
Brewster, LL. D. F. R. S. Lond. & Sec. R. S. Edin. 1 
Narrative of a Descent in the Diving-Bell, &c. &c. By 
Dr Louis Theodore Frederick Colladon of Ge- 
neva, Hon. Mem. R. I. A. M. W. S. &c. - 8 
1 I Remarks on a Passage in the Mathematical Collections 
of Pappus, from which the Obliquity of the Ecliptic 
has been deduced, - - 1.5 
i . Account of the Atush Kudda, or Natural Fire Temples 
of the Guebres, formed by Burning Springs of 
Naphtha, with a Notice respecting the Naphtha 
Wells in Pegu, - - - 21 
On Isothermal Lines, and the Distribution of Heat over 
the Globe. By Baron Alexander de Humboldt, 28 
Description of Water-Spouts observed by the late Mr 
Maxwell. Extracted from his MS. Journal, 39 
I On the Diminution of the Obliquity of the Ecliptic, 42 
^ l Observations on the Countries of Congo and Loango 
as in 1790. By Mr Maxwell, Author of the Let- 
ters to Mungo Park, &c. <&c. - -45 
Account of an Improved Apparatus for restoring the 
Action of the Lungs. By Mr John Murray, F.L.S. 53 
Account of the Rousts or Currents of Tide in the Pent- 
land Frith, &c. from the Manuscript Journal of the 
late Rev. George Low of Orkney. With Preli- 
minary Observations by Samuel Hibbert, M. D. 
F. R. S. E. &c. &c. 
55 
