il. PREFACE. 
judicious arrangement of materials. To apply - 
properly the new facts dispersed in the follow- 
ing work, I have been under the necessity of 
taking rather an extended view of the Animal 
Economy ; but as there is no separate work on 
Irritability, in the Medical Literature of this 
country, I felt impressed with the idea, that such 
a publication, if tolerably well executed, would 
eventually be acceptable. 
At present, there are no Medical authorities 
more highly esteemed than Haller and Bichat; 
and if I had written merely for a local or 
transitory popularity, it would probably have 
been more judicious to make a compilation of their 
works, than to controvert their opinions. But 
literature imvariably decays, when the authority 
of authors preponderates over the authority of 
Nature. “ In the same manner,” if I may use the 
words of Longinus, “ as children always remain 
pigmies, whose infant limbs have been too closely 
confined; thus our tender minds, fettered by a 
just servitude, are unable to expand themselves, 
or attain that well proportioned greatness which 
we admire in the ancients.” Such, in some 

