AS A MANURE. Q^\ 



tif the other ingredients of the aflies left after lixiviation may 

 prove beneficial, yet the effects are chiefly from the cinis, or 

 new named earth. 



* This earth, which is fo prized in America as a manure, 

 was efleemed of old in Afia, as an ingredient in a cement: 

 among the ancient Syrians, it was one of the materials form- 

 ing the platter of their walls; and as it holds an intermediate 

 place between lime and potafh, it can eafily be conceived 

 how it may a& both as a cement and a manure. It is to be 

 hoped, chemifts will turn their attention to this important 

 fubjecV' See Tilloch's Philof. Magazine, Vol. VII. p. 273, 

 for the whole of this inlerefting letter. 



3. Several Metallic Salts promote Vegetation, Jhezvn by the fcx* 

 periments of Profefibr Barton, of Philadelphia. 



Letter from Benjamin Smith Barton, M. D. Prqfejfor of Medicine 

 in the College of Philadelphia, to Dr. Pearfon, containing 

 Experiments with Metallic Solutions to determine their Effects 

 on Plants, 



Stk, 



Philadelphia, OB. 23, 1802i 



IN the Annals of Medicine for the year 1801, you inform D?re<A expert- 

 ujj that you have lately read a paper at the Board of Agricul- S 7 m t^ 

 ture, " containing an account of the effe&s of a faline body falts on vegeta- 

 collected from peat, as a mod powerful manure, which turns tl0n ' 

 out to be fulphate of iron ; a fubftance (you remark) hitherto 

 confidered to be a poifon to plants." This piece of intelligence 

 gave me much fatisfaction. I have, for fome years, been 

 engaged in an extenfive feries of experiments, relative to the 

 effects of various fiimulating articles, fuch as camphire, &c. 

 upon vegetables; and on the abforption of certain powerful 

 mineral lubfiances into the organic fy (rem of vegetables. In 

 numerous infiances I have fubje&ed the ftems and leaves of 

 plants, young and old, large and fmall, to the influence of the 

 fulphates of iron and copper. I have found, that both of 

 thefe metallic falts are very greedily abforbed by vegetables., 

 infomuch that I have detected the prefence of iron in the 

 veflels of a branch of mulberry, at the height of five or fix 

 feet above the place of immerflon in a folution of the fulphate 

 of this metal. A full account of my experiments, I defign 



Vol. X.— April, 1S05. P* t# 



