1 12 On Planter of Paris, 



cultural uses, seems to be founded in mere theory. For 

 we find by experience^ of which theory is only the pupil: 



1. That the gyps succeeds on limed land^ quite as 

 well as on that not limed ; and some think better. 



2. Although we never analyze chemically, to know 

 the balance between the aac/and the calcareous earth in 

 our plaister, we find that the gyps, out of the same par- 

 cel, does as well on limed, as on other land, let whatever 

 parts of the substance prevail in its composition. 



3. As to its alleged disagreement with alkalis, we 

 do not find this, by any means, founded in fact. I have 

 plaistered land previously manured with soap boilers 

 ashes, and it has not only done well, but I think has had 

 remarkable success. 'Tis true these ashes are mixed 

 with lime, and the alkali weakened by lixivation. But 

 General Hand has placed the fact beyond a doubt. See 

 pages 30, 31. He strewed ten or twelve bushels of 

 (wood) ashes to the acre, which is much more than I 

 ever strew per acre, for grass. The plaister, he states, 

 had more effect, than it Iiad on ground dressed with other 

 manure. Why it is so, is not of so much consequence, 

 as the fact itself. But if the foregoing theory were pur. 

 sued, we should find encouragement from the proper- 

 ties of «//ra/f5. Chaptal, pages 115, 11 9, 120, [Philadel- 

 phia edition] " all alkalis contain carbonic acid and are 

 considered as carbonates, Hydrogene and nitrogene gas 

 may be produced from mineral; and carbonic, from all 

 alkalis y In other chemical writers it appears, that the 

 salt found in ashes, may be purified, so as to contain 

 half its weight oi fixed air. Beside that it may be pre- 

 sumed that vegetable alkalis furnish the most carbonc, 

 it appears, that in both mineral and vegetable alkalis, the 



