9 1 Dr. Crawford's Theory. [Book II. 



cerning the generation of heat within animal bodies, 

 which he confiders as derived from the air we breathe. 

 The air being condenfed on the lungs, the heat which 

 it contained in a latent ftate is abforbed and difperfed 

 over the animal body. But this is a fubjedl which 

 properly belongs to another part of the work. 



jiedlion with the fubjel. No man was ever better calculated for 

 promoting ufeful fcience than Dr. Crawford. In him induftry and 

 perfeverance were eftablilhcd habits; and candour and caution 

 charafteriflic difpofitions. With all the advantages of a liberal 

 education, he united great natural fagacity, acutenefs, and inge- 

 nuity ; yet the laft quality was tempered by a coolncfs and collecV 

 ednefs of mind, which effectually prevented his too hailily acced- 

 ing to the rafli conclufions of plauiible theory. With all his excel- 

 lence as a fcientific -man, he poilefled the gentleft of tempers,, the 

 moft friendly heart. From his promifed revifion of this work, I 

 had flattered myfelf with great advantages; but what arc private 

 lofles compared with that of the public ! If, after having ferved his 

 country in a public capacity, the family of fuch a man mould be 

 left in indigence, to what a itate is the national fpirit reduced \ 



