CHAP. IT.] of Plants. Du Hauicl. 489 



nature, as were Malpighi, Mariotte or Hales ; compared with 

 those great thinkers he was only a compiler, and a somewhat 

 uncritical one. But he was not a dilettante in science, like 

 Bonnet ; he made the vegetable world the subject of serious 

 and diligent study, and he endeavoured to turn the results 

 of that study to practical account. Long familiarity with plants 

 gave him a kind of instinct for the truth in dealing with them, 

 ?s is shown in his observations and experiments, many of 

 which are still instructive ; but he had neither that faculty 

 of combination which can alone bring a meaning out of 

 experiments and observations in physiological investigations, 

 nor the power to distinguish between matters of fundamental 

 and secondary importance. So thinks also his biographer 

 Du Petit-Thonars. 



The merits and the faults here mentioned are combined in 

 an especial degree in Du Hamel's most famous work, ' Phy- 

 sique des arbres,' which appeared in two volumes in 1758 and 

 is a text-book of vegetable anatomy and physiology with 

 numerous plates. His remarks on the nutrition of plants 

 and the movement of the sap are a lengthy compilation chiefly 

 from Malpighi, Mariotte and Hales, though he has not suc- 

 ceeded in appropriating .exactly that which is theoretically 

 important or adopting the most commanding points of vie\v. 

 He introduces the results of his own experiments into his 

 account, and these are often instructive in themselves, but are 

 never made use of to establish a definite view with respect 

 to the connection between the processes of nutrition. He 

 hits upon the right view only when he is dealing with plain 

 and obvious matters ; for instance, he restores the vessels 

 of the wood to their old rights, and concludes from e\|>< r i 

 incuts, as had been already done in the 17th century, that 

 an elaborated sap moves in the reverse direction in the rind ; 



on presenting to it an essay on .1 disease then raging in the saffron-plantations, 

 and caused by the growth of a fungus (' Biographic Universelle '). 



