J5T. 22.] ACQUISITION OF KNOWLEDGE. 43 



Essex, whence it would range " in a south-west direction 

 by Henley-on-Thames to near Hungerford, when, turn- 

 ing abruptly eastward, it bends by Guildford, Croydon, 

 and thence in an irregular line near Chatham and 

 Canterbury to the South Foreland. The reason for 

 adopting so large and irregular a district is that the 

 zoological and botanical distributions are materially 

 influenced by geological superposition, and that the 

 development of the latter would be extremely incom- 

 plete were the limits more restricted/' 



The following extract is from a letter to an old Head- 

 ing schoolfellow, Mr Edward Hurry, at Bogota : 



J. Prestwich to E. Hurry. 



BIRMINGHAM. Oct. 1834. 



MY DEAR EDWARD, ... I must again return you my best 

 thanks for your kind endeavours to procure for me such minerals 

 and fossils as you may meet with. The district in which you are 

 now situated affords few or none of these, but the sea, I should 

 think, would abound with a great variety of corals, shells, sea- 

 weeds, &c. specimens of all of which would be highly accept- 

 able. That which to you appears trifling and valueless from 

 the circumstance of its being commonplace and abundant would 

 be of much interest here. No object of natural history will come 

 amiss. 



The letter is a long one, giving news of Dr Valpy, 

 and reminiscences of schoolboy days at Reading. 



Mr E. Hurry in reply deplored his lack of knowledge 

 of geology and mineralogy, and besought his old school- 

 fellow to put him in the way of acquiring it, adding 

 that he had sent to England for a book on the subject 

 for study. We find ten pages of large letter-paper 

 a closely written document without date, beginning 

 " My dear Edward," which was the draft of a letter 

 of instruction sent to Mr Hurry at Carthagena. After 



