Br. U^nll on the Thancmenay &c. 435 



it adds frefh beauty to the parterre, and gives 

 new dignity to the foreft. 



It only rennains, that I excufe myfelf for wri- 

 ting on a botanical fubjecl, when I am a can- 

 didate for medical honours. A few words will 

 fufTice. Such is the analogy between vegetables 

 and animals, that the knowledge of the nature 

 of the one illuftrates that of the other : and as 

 vegetables, in every part of the world, form a 

 great part of our food, as well as of our medi- 

 cines, it is highly important for every phyfician 

 to be well acquainted with their nature. 



Sofne Observations on the Ph-^enomena, ivhich 

 take Place between Oil and Water, in a 

 Letter to Thomas Percival, M.D. F.R.S, 

 and S.A. ^c. By Martin Wall, M.D. 

 Pr alegar of Chem'Jlry in the Univerfity of Oxford, 

 Read Nov. 17, 1784. 



D X. A R S I R, 



np H E adlion of bodies on each other, the 



**■ principles upon which that adion depends, 



and the caufcs, v;hich under certain circum- 



ftances diminifh, impede, or prevent it, have 



F f 2 defervedly 



