On the Excrementitious Matter thrown off by Plants. 267 
Arr. XI.—On the Excrementitious matter thrown off by Plants ; 
by J. Buru. 
I have read, with much interest, the opinions lately advanced by 
De Candolle, Macaise, and I believe by Professor Lindley, in re- 
gard to the excretory powers of plants. I fully acquiesce in the 
statement that plants throw off, into the soil, excrementious matters, 
not congenial to their wants; but I cannot accede to the other part 
of their theory, viz.—that these matters are poisonous to the species 
which gives them off, and that from this cause arises the necessity 
of an alternation in farm crops. I will briefly state my reasons for 
this dissent, and shall be happy to be corrected by any of your cor- 
respondents, if I am in the wrong. 
I venture to assert, in the first place, that in forests and uncultiva- 
ted grounds, the same plants, annuals as well as perrenials, are found 
growing in successive years, without apparent deterioration, af the 
plants are permitted to remain and decay where they grow. It is 
not what grows upon the ground, but the crop which is carried off, 
that impoverishes the soil. We find an additional illustration of this 
truth, upon waste ground around farm buildings, where we often 
see the bur dock, nettle, hemp and other plants, grow up fall and 
decay, for years, and each successive growth increases, rather than 
diminishes in vigor. 
American husbandry furnishes facts no less apposite to my argu- 
ments. Ina large section of Western New York, comprising a dis- 
trict of sixty, or more, miles square, it is a very common practice to 
grow wheat, in the same field, for successive years. On a recent 
visit to that district, | put the question to an intelligent circle of gen- 
tlemen, ‘‘ how many years in succession has wheat been grown upon 
any of your lands?” One case was cited where it had been grown 21 
or 22 years. A gentleman then alluded to aneighbor, who had 
grown wheat 22 years without intermission, on one field, and the 
fact was accredited and confirmed by others. ‘‘ And what, I asked, 
was the product of the last season?”’ ‘‘ Forty bushels to the acre,” 
was the answer. ‘‘ Was manure applied?” <‘‘ No.” 
In another district of the State, comprising the south towns of 
Erie and Chautauque Counties, oats constitute a favorite crop; and 
they are grown many successive years on the same ground, without 
diminution of product. 
