SIR J. E. SMITH. 



71 



Ray joined him in September 1668, and remained for 

 most part of the ensuing winter and spring. 



The seclusion and leisure of the country, with the con- 

 verse and assistance of such a friend were favorable to the 

 prosecution of a new subject of inquiry, which now 

 strongly attracted the attention of our great naturalist — 

 the theory of vegetation. The first step of the two 

 philosophers in this little-explored path, was an examina- 

 tion of the motion of the sap in trees, and the result of 

 their inquiries communicated to the Royal Society ap- 

 peared soon after in the Philosophical Transactions. Their 

 experiments clearly prove the ascent of the sap through 

 the woody part of the tree, which is easily detected by 

 boring the trunk at different depths before their leaves 

 are unfolded, and they observed also the mucilaginous 

 nature of the flowing sap, " precipitating a kind of white 

 coagulum or jelly, which," says Ray, in a note preserved 

 by Derham, "may be well conceived to be the part which 

 every year between bark and tree turns to wood, and of 

 which the leaves and fruits are made. And it seems to pre- 

 cipitate more when the tree is just ready to put out leaves 

 and begins to cease dropping, than at its first bleeding." 

 The accuracy of the leading facts recorded by these in- 

 genious men is confirmed by subsequent observers, who 

 have further pursued the same subject, which is now suf- 

 ficiently well understood. They, indeed, like the rest of 

 the world, till lately, seemed not to have suspected that 

 the sap was quiescent till their perforations in the tree 

 were made ; nor did they advert as they ought to phe- 

 nomena dependent on the principle of life in the vege- 

 table body. 



At this time Ray began to prepare for the press his 

 ' Collection of Proverbs,' a curious book in its way, by 

 which he is perhaps better known to the generality of his 

 countrymen than by any other of his literary labours. 



The first edition was published in 1672, but the work 

 was subsequently much enlarged, and the author may 

 almost be said to have exhausted his subject. From its 



