INTRODUCTION TO NEW EDITION. XV 



of England, to ascertain, among other things, whether manure 

 from sheep receiving an allowance of cotton-seed cake is any 

 richer than that from sheep, otherwise fed alike, but having, 

 instead of cotton-seed cake, the same amount of corn meal. We 

 know that such manure contains more nitrogen, and other 

 plant food, than that from the corn meal. But the experiments 

 so far, though they have been continued for several years, do 

 not show any striking superiority of the manure from cotton- 

 seed cake over that from corn meal. I saw the wheat on these 

 differently manured plots in 1879. Dr. Voelcker and Dr. Gil- 

 bert, told me that, one of two plots was dressed with the cot- 

 ton-seed manure, and the other with 'the corn meal manure, 

 and they wanted me to say which was the most promising 

 crop. I believe the one I said was the better, was the cotton- 

 seed plot. But the difference was very slight. The truth is 

 that such experiments must be continued for many years before 

 they will prove any tiling. As I said before, we know that the 

 manure from the cotton-seed cake is richer in nitrogen than 

 that from the corn meal ; but we also know that this nitrogen 

 will not produce so great an effect, as a much smaller amount 

 of nitrogen in salts of ammonia, or nitrate of soda. 



In going over these experiments, I was struck with the 

 heaUhy and vigorous appearance of one of the plots of wheat, 

 and asked how it was manured. Dr. Vcelcker called out, 

 " clover, Mr. Harris, clover." In England, as in America, it 

 requires very little observation and experience to convince any 

 one of the value of clover. After what I have said, and what 

 the Deacon, the Doctor, Charley and the Squire have said, in 

 the pages of this book, I hope no one will think that I do not 

 appreciate the great value of red clover as a means of enrich- 

 ing our land. Dr. Voelcker evidently thought I was skeptical 

 on this point. I am not. I have great faith in the benefits to 

 be derived from the growth of clover. But I do not think it 

 originates fertility ; it does not get nitrogen from the atmos- 

 phere. Or at any rate, we have no evidence of it. The facts 

 are all the other way. We have discussed this question at 

 considerable length in the pages of this book, and it is 

 not necessary to say more on the subject. I would, however, 

 particularly urge farmers, especially those who are using phos- 

 phates freely, to grow as much clover as possible, and feed it 

 out on the farm, or plow it under for manure. 



The question is frequently asked, whether the use of phos- 

 phates will ultimately impoverish our farms. It may, or it may 



