136 



DK. 1ST. H. J. MILLER ON THE AMOUNTS OF [May I9O3, 



to know, at any rate approximately, how much of the total organic 

 matter in our soils is humous and how much bituminous — in other 

 words, to what extent, if at all, the organic matter of the original 

 deposit is an immediate product of the usual processes of decay of 

 vegetable matter, or whether it has undergone the more drastic 

 treatment under which coal and allied substances have been produced. 

 A good deal may be learned by a study of the subsoils, as even a few 

 feet below the surface comparatively little of the organic matter 

 can be due to recent vegetation ; but a systematic examination of 

 deeper deposits is very desirable in this connection. 



The large areas of peat-land known as 'Hochmoor' contain 

 relatively little nitrogen near the surface, but much more a few feet 

 below. Detmer x tabulates the following analyses (calculated as 

 percentages in the substances free from ash) of peat from Jessbeck 

 in Schleswig-Holstein : — 



Table TV. — Composition op Peat at Different Depths. 





Organic 

 Carbon. 



Total 

 Nitrogen. 



Hydrogen. • Oxygen. 



Carbon 



to lof 



Nitrogen. 



Nitrogen 



to 100 of 



Carbon. 



Surface 



7 feet deep . . . 

 14 feet deep ... 



Per cent. 

 5775 

 62-02 

 6407 



Per cent. 

 0-80 

 2-10 

 4-05 



Per cent. Per cent. 

 5-43 36-02 

 521 30-67 



5-01 | 2687 



72-2 

 29-5 

 15-8 



1-4 

 3-4 

 6-3 



We possess, of course, no evidence that the vegetation from which 

 the lower layers of the peat are derived was identical in composition 

 with that of later growth. But the high percentage of nitrogen at a 

 depth of 14 feet must be mainly due to losses of oxygen in com- 

 bination with carbon, as well as to losses of hydrogen, probably as 

 marsh-gas. The original peat contained 2*72, 7*42, and 9*16 per 

 cent, of mineral matter respectively at the different depths. 



A more detailed examination of the non-nitrogenous matter of 

 peat was made by Dr. Hjalmar von Feilitzen, 2 and his results 

 ■•onrirm those of Detmer, as regards the gradual increase in the pro- 

 portion of carbon concurrently with the increase in depth, notwith- 

 standing that the peat rapidly loses two prominent non-nitrogenous 

 constituents — cellulose and furfuroids. The peats investigated by 

 H. von Peilitzen were of the ' Hochmoor ' variety, derived from 

 vegetation which thrives when the surrounding water is deficient 

 in lime and other mineral plant-food. Absence of lime has been 



1 Landw. Versuchs-Stationen, vol. xiv (1871) p. 271. 



2 Journ. Landw. vol. xlvi (1889) ; see also Hj. von Feilitzen & B. Tollens, 

 Ber. Deutsch. Chem. Gesellscb. vol. xxx (1897) p. 2571. 



