Ixiv PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



of pressure in modifying the forms of fossils ; the first great fact on 

 which Mr. Sharpe fomided his theory being thus brought within the 

 bounds of calculation. 



I have treated this subject at some length, because the two papers 

 of Mr. Sharpe upon cleavage must always be reckoned amongst his 

 most striking contributions to science ; though it is feared that his 

 success in explaining cleavage and assigning it to an efficient cause 

 may sometimes have induced him to push the fact itself beyond its 

 true limits, as in his paper on Scotland in the Transactions of the Royal 

 Society, and in his paper on the Alps. I have thus endeavoured to 

 do justice, though imperfectly, to the labours of Daniel Sharpe, and 

 I will only add, that his quiet humour, his manly straightforward 

 assertion of truth, and his well-known liberality and benevolence 

 endeared him to us as a friend, whilst his shrewd discernment, his 

 accurate observation, and his extensive knowledge made us admire 

 him as a philosopher and geologist. 



Sir Alexander Crichton, second son of Mr. Alexander Crich- 

 ton, and grandson of Mr. Patrick Crichton, of Woodhouselee and 

 Newington, Mid-Lothian, was born in Edinburgh on the 2nd of De- 

 cember, 1 763. He received his elementary education in the Canon- 

 gate and High schools of his native city, and afterwards matriculated 

 at its University. He was about the same time apprenticed to Mr. 

 Alexander Wood, a surgeon of considerable eminence in Edinburgh. 



In 1 784 Mr. Crichton went to London for one year to attend the 

 hospitals, and to prosecute his studies, more particularly anatomy, 

 in the schools of the metropolis. At the expiration of the year he 

 went to Leyden, in company with Mr. Robert Jackson, a young 

 army surgeon, who afterwards became favourably known for his 

 writings on subjects connected with Military Surgery. Although 

 brought up to consider the practice of Surgery his vocation, Mr. 

 Crichton thought it advisable to submit himself to the necessary exa- 

 minations before the professors of Leyden University for the Degree 

 of M.D., which he obtained in July 1 785. (The subject of his inau- 

 gural Thesis was *' De Vermibus Intestinorum.") 



After passing a short time in Holland, he proceeded to Paris to 

 perfect himself in the French language, and avail himself of the fa- 

 lities for advancement in every department of medical knowledge 

 which that capital afforded. In the summer of the following year 

 Dr. Crichton was prevailed upon by his friend, Dr. Pringle, to give 

 up his original plan, and to accompany him to Stuttgard, in order 

 that they might study the language of the country. At the expira- 

 tion of three months, agreeably and profitably spent, the two friends 

 separated. Dr. Pringle to return to Alnwick, and Dr. Crichton to 

 proceed to Vienna, where he remained six months, and gained much 

 practical information by daily attendance at the General Hospital of 

 that city. The University of Halle in Saxony was next visited, 

 where Dr. Crichton resided three months in the house of the cele- 

 brated anatomist Meckel, and thence proceeded to Berlin ; and in 

 March 1 788 to Gottingen, which he left on the 20th of September of 



