Preface. vii 



they would here acknowledge, especially to the late Dr. 

 BENCE JONES of London, to Professor J. DUMAS of Paris, to 

 Professor JULES MARCOU of Cambridge, and to Dr. GEORGE 

 E. ELLIS of Boston ; and the Life of Benjamin Thompson, 

 Count Rumford, prepared by Dr. Ellis at the request of the 

 Academy, forms the fifth volume of this series. 



In arranging the papers of Count Rumford in the several 

 volumes of this edition of his works, the Rumford Committee 

 have grouped together, as far as was practicable, the papers on 

 allied subjects : thus, the scientific papers will be found chiefly 

 in the first two volumes ; descriptions of improved methods 

 of warming and cooking occupy the third ; and the greater 

 part of the last is devoted to the philanthropic essays ; but 

 this also contains the scientific papers on light. Owing, 

 however, to the accession of new material while the work 

 was passing through the press, it has not been possible to 

 follow strictly the plan originally adopted, and for the same 

 reason the size of the last volume is proportionally large. 

 The work is stereotyped ; and in conclusion the Rumford 

 Committee would request that any additional matter that 

 may be discovered, or any errors in the text of this edition, 

 may be reported to them, in order that the additions or cor- 

 rections may be made in future imprints from the plates. 

 Such communications should be addressed to the RUMFORD 

 COMMITTEE, American Academy of Arts and Sciences, Boston, 

 Massachusetts, U. S. A. 



JOSIAH P. COOKE, JR., Chairman. 

 JAMES B. FRANCIS. 

 WOLCOTT GIBBS. 

 E. C. PICKERING. 

 JOHN M. ORDWAY. 

 STEPHEN P. RUGGLES. 

 MORRILL WYMAN. 



