417 



their study teaches nothing of the uses of plants. On the 

 other hand, physiologists, in their investigations of the ve- 

 getable as well as animal kingdoms, have fallen into errors 

 and laboured under many disadvantages, for want of accu- 

 rately knowing one thing from another ; just as mere prac- 

 tical or empirical observers or collectors of plants, so far 

 from noticing any circumstance that might lead by reason 

 or analogy to assist their inquiries, very often, from the 

 neglect of the clearest principles, commit the most absurd 

 mistakes. Thus I have known Chervil gathered for Hem- 

 lock, the purple Ly thrum for the Digitalis, and Creeping 

 Crowfoot for the Fiorin Grass. The great physiologist 

 Spallanzani made observations upon young aquatic snails, 

 which had not yet acquired their shells, mistaking them 

 for the vegetable Tremella; and proved, by learned de- 

 duction, that the said Tremella, or rather the snails, were 

 of an animal nature ; nor was he at all pleased at being- 

 set right in this matter of fact. 



We are indebted to the Italian philosophers of the seven- 

 teenth century, especially to Malpighi, for the first con- 

 siderable information respecting the anatomy or internal 

 structure of the vegetable body ; though our ingenious 

 countryman, Dr. Grew, nearly about the same time was 

 intent on the same subject. In the next century their facts 

 and observations, assisted by new ones, were made good 

 use of by physiologists, properly so called, — such as 

 Hales, Blair, Bradley, and our immortal Newton himself, 

 in England ; and more recently by Du Hamel and Bonnet, 

 with a number of less original writers, on the continent. 

 Labourers in this field of science have, for some time past, 

 not been wanting, though much yet remains to be done. 

 Every hand is not alike successful in advancing the pro- 

 gress of real knowledge. Those who have had some par- 

 ticular object in view, as the uses of the stamens and 

 pistils of plants, or the theory of their reproduction, have 

 paid little regard to the physiology of other parts, — as the 

 calyx, corolla, or foliage. So, with respect to classification, 



VOL. II. 2 E 



