Agricultural Chemistry. 317 



According to this definition, which is entirely unknown to 

 science, a refutation of my doctrine was easy. 



When I spoke of all progress in agriculture depending on our 

 being able to replace farmyard-manure by its efficient inorganic 

 constituents, Mr. Lawes, resting on his erroneous definition, 

 proved that I had maintained tliat ice should exclude ammonia 

 from the manure, BECAUSE AMMONIA is AN ORGANIC COMPOUND ! ! 



And when, in my ' Principles,' p. 90, I said that his experi- 

 ments included the proof that farmyard-manure (organic manure) 

 could be replaced, in its entire efficacy, by mineral substances 

 (for sulphate of ammonia and sal ammoniac, are mineral sub- 

 stances), he replies, — 



" Thus, then, ammoniacal salts, sulphate of ammonia, and sal 

 ammoniac, are to be classed as mineral manures ! This is 

 indeed begging the question: but a manoeuvre so transparent as 

 this would not even require notice, were it only addressed to the 

 scientific reader." (' On some Points,' &c.. Journal, vol. xvi. 

 p. 447.)* 



And when, in the same little work, as I had always done in my 

 book, and as was indispensable to the understanding of it, I con- 

 sidered ammonia and the constituents of the ashes of plants as 

 contrasted, in the sense of air and earth (atmospheric and terres- 

 trial food of plants), Mr. Lawes ventures to assert, that / have 

 regarded them as contrasted in his sense, and HAVE ALWAYS 



CONSIDERED AMMONIA AS AN ORGANIC SUBSTANCE, which, from my 



point of view, was a sheer impossibility ; and he calls my expla- 

 nation a ruse .' ' " The ruse," says he, " has not been entirely 

 without success," — (p. 448.) 



His last paper in this Journal is a carefully prepared attempt, 

 not only to call in question my scientific qualifications in these 

 matters, but also to cast suspicion on my veracity, as if a career 

 of thirty-four years of the most earnest and laborious efforts, 

 entirely devoted to science and to the welfare of mankind, were 

 not a sufficient protection against such unworthy insinuations. 



The history of agriculture will be a severe judge in these 

 matters. I know well the defects and imperfections of my book, 

 but no one shall ever be able justly to accuse me of not having 

 endeavoured, with the best will and with all my power, to ascer- 

 tain the truth, and to correct the errors into which I may have 

 fallen. On the very first opportunity that offered, I admitted 



* I must refer the reader to the last note for proof that the doctrine here 

 represented as a nianccuvra by Mr. Lawes was held and has always been taught 

 by me, not only in 1843, but niucli earlier. In m\' Lectures, in eoinnioii, I 

 believe, with all teaciiers, I constantly represent tlie vefietable kingdom as 

 building up organic matter from inorganic substances, and the animal kingdom 

 (with decay and combustion) as reconverting organic substances into the inorganic 

 food of plants. — W. G., Translator. 



