56 love's meinie. 



grew's on the Whig; * — and now I must qualify my praise 

 considerably, discovering, when I examined the book far- 

 ther, that the good doctor had described the motion of a 

 bird as resembling that of a kite, without ever inquiring 

 what, in a bird, represented that somew^hat important part 

 of a kite, the string. You will, however, find the book full 

 of important observations, and illustrated by valuable draw- 

 ings. But the point in question you must settle for your- 



* " On the Physiology of Wings." Transactions of the Royal Society 

 of Edinburgh. Vol. xxvi. , Part ii. I cannot sufficiently express either 

 my wonder or regret at the petulance in which men of science are con- 

 tinually tempted into immature publicity, by their rivalship with each 

 other. Page after page of this book, which, slowly digested and taken 

 counsel upon, might have been a noble contribution to natiu'al history, 

 is occupied with dispute utterly useless to the reader, on the question 

 of the priority of the author, by some months, to a French savant, in 

 the statement of a principle which neither has yet proved; while page 

 after page is rendered worse than useless to the reader by the author's 

 passionate endeavour to contradict the ideas of unquestionably previous 

 investigators. The problem of flight was, to all serious purpose, solved 

 by Borelli in 1(580, and the following passage is very notable as an 

 example of the way in which the endeavour to obscure the light of 

 former ages too fatally dims and distorts that by which modern men of 

 science walk, themselves. " Borelli, and all who have written since his 

 time, are unanimous in affirming that the horizontal transference of 

 the body of the bird is due to the perpendicular vibration of the wings, 

 and to the yielding of the posterior or flexible margins of the wings in 

 an upward direction, as the wings descend. I" (Dr. Pettigrew) '"am, 

 however, disposed to attribute it to the fact (1st), that the icings, both 

 when elevated and depressed, leap forwards in curves, those curves 

 uniting to form a continuous waved track ; (2nd), to the tendenGy ichieli 

 the body of the bird has to sioinff forwards^ in a more or less horizontal 

 direction, when once set in motion ; (3rdi, to the con.struction of the 

 wings ; they are elastic helices or screws, which twist and untwist 

 while they vibrate, and tend to bear vpwards and onwards any weight 

 suspended from them; (4th), to th£ reactimi of the air on the under sur- 



