JET. 83.] A CHALLENGE. 389 



was the last appearance in public of any communication 

 from Joseph Prestwich. His first memoir, when a 

 young, hard - working City man, had been read to 

 the Geological Society in 1834 : now, after a splendid 

 record of sixty-one years' continuous original work, his 

 pen for the public was laid aside. 



In the letter to the ' Geological Magazine ' he re- 

 futes the theory of the flint implements from the 

 Chalk plateau of Kent having been formed by natural 

 agencies, and observes : " Had it been possible for sea- 

 or river-action to have produced such forms as those 

 I have figured in Plates V. to IX. of ' Collected Papers,' 

 they should be found in all such shingle of whatsoever 

 age. None are forthcoming." He repeats a former 

 challenge : " [I] am ready to exchange the two volumes 

 of ' Geology ' with any young (or old) dissentient, for 

 half-a-dozen shore flints (not derived) of any of the 

 plateau types figured in the five plates above named." 

 No one has come forward or has accepted the chal- 

 lenge. Time will adjudge the verdict, and of it we 

 are not doubtful. 



This imperfect sketch of the life of Joseph Prestwich 

 would be still more incomplete without special reference 

 to the affectionate relations which were maintained 

 between him and geologists abroad, more particularly 

 with those in France and Belgium. These friendships 

 were not those of a year or so, or a score of years, but 

 were life-enduring. His position as an Englishman of 

 science among French savants was through a long series 

 of years probably unique. In the files of letters from 

 Gaudry, Daubree, Hebert, and other distinguished 

 members of the Institute, we find Joseph Prestwich 

 repeatedly addressed by the first-named as " Mon cher 

 maitre" "Cher et illustre confrere"; Deshayes wrote 



