CONTENTS. 
IX. Analytical Experiments and Observations on Lac. By 
Charles Hatchett, Esq. F. R.S. p. 191 
X. On the Integration of certain differential Expressions , with 
which Problems in physical Astronomy are connected , &c. By 
Robert Woodhouse, A. M. F. R. S. Fellow of Caius College. 
p. 219 
XI. Observations on Basalt, and on the Transition from the 
vitreous to the stony Texture, which occurs in the gradual Refri- 
geration of melted Basalt ; with some geological Remarks. In 
a Letter from Gregory Watt, Esq. to the Right Hon. Charles 
Greville, V. P. R. S. p. 279 
XII. An Analysis of the magnetical Pyrites; with Remarks on 
some of the other Sulphurets of Iron. By Charles Hatchett, 
Esq. F. R.S. P- 315 
XIII. Remarks on the voluntary Expansion of the Skin of the 
Neck, in the Cobra de Capello or hooded Snake of the East 
Indies. By Patrick Russell, M. D. F. R. S. With a Description 
of the Structure of the Parts which perform that Office. By 
Everard Home, Esq. F. R. S. p. 34 6 
XIV. Continuation of an Account of the Changes that have hap- 
pened in the relative Situation of double Stars. By William 
Herschel, LL. D. F. R. S. p. 353 
