CONTENTS. 
XIX. On a Periscopic Camera Obscura and Microscope. By 
William Hyde Wollaston, M. D. Sec. R. S. p. 370 
XX. Further Experiments and Observations on the influence of 
the Brain on the generation of Animal Heat. By B. C. Brodie, 
Esq. F.R.S. Communicated to the Society for promoting the 
knowledge of Animal Chemistry, and by them to the Royal 
Society . p. 378 
XXL On the different Structures and Situations of the Solvent 
Glands in the digestive Organs of Birds , according to the nature 
of their Food and particular Modes of Life. By Everard 
Home, Esq. F. R. S. p. 394 
XXII. On some Combinations of Phosphorus and Sulphur, and on 
some other Subjects of Chemical Inquiry. By Sir Humphry 
Davy, Knt. Sec. R. S. p. 405 
Presents received by the Royal Society , from November 1811 to 
June 1812. p. 417 
Index. p. 421 
ERRATA. 
Of the figures intended to illustrate Mr. Playfair’s paper in the last volume of 
the Transactions, Fig. 3 is named by mistake Fig. 1. Fig. 1 was omitted by accident, 
and is to be found at the end of this Part of the Transactions. 
Philosophical Transactions, 181 1, page 230, line 13 , J ’or 8 h 35' 45" read 8 h 2' 5". 
Page 151 of this volume of the Transactions, line 20, for half read double. 
