Address before the Association of American Geologists. 263 



ing their nature we find, as we might expect, that distinguished 

 chemists differ somewhat in their conclusions. BerzeHus in- 

 cludes all the organic matter of soils under the term humus. In 

 this he supposes that he finds crenic, apocrenic, and humic acids, 

 with extract of humus and humin. This was his view of the 

 subject, if I understood it, in 1840 ; and it does not diff"er from 

 his views seven years before, except in substituting recently the 

 term humic acid for geine, and humin for carbonaceous mould. 

 In this country, Dr. S. L. Dana employs the term geine in two 

 senses. When he speaks agriculturally, he means by it "all 

 the decomposed organic matter of the soil," which he divides 

 into the soluble and insoluble ; and in this sense he regards cre- 

 nic and apocrenic acids, humin and extract of humin, as forms of 

 geine. When he speaks chemically, he regards geine as a distinct 

 compound, the same in composition as the substance denominated 

 geine by Berzelius in 1833, and humic acid in 1840 ; although 

 he supposes the humin and carbonaceous mould of the same chem- 

 ist to be identical with humic acid, and of course only varieties 

 of geine. Dr. Jackson, however, contends that geine is not a dis- 

 tinct compound, and that it is essentially composed of crenic and 

 apocrenic acids. I mention these facts, not with a view to enter 

 at all in this place, into the discussion of these points, but merely 

 to call the attention of gentlemen to them as matters of great in- 

 terest. I am too well acquainted with the gentlemen who have 

 adopted different views on these subjects, not to believe that they 

 will thankfully accept of light from any quarter, and consider it 

 an honor, rather than a disgrace, to give up opinions which exper- 

 iment or sound argument shows to be untenable. For they well 

 know, that in a progressive science, like agricultural chemistry, 

 the honor of original discovery belongs to him who makes an ad- 

 vance u})on his predecessors ; nor can it pluck the laurel from his 

 brow, although others aided by his labors, should subsequently go 

 beyond him. In the present case it may be thought, that rules 

 for the analysis of soils, founded upon different views of the char- 

 acter of their organic matter, must be useless. But I must ex- 

 press the opinion, that the agricultural value of analyses, conduct- 

 ed according to these conflicting views, cannot be very different ; 

 and in a scientific respect, in the present state of agricultural 

 chemistry, analyses performed in different modes must be an im- 

 portant means of arriving ultimately at the truth. 



