BULLETIN OF THE BUSSEY INSTITUTION. 269 
It is undoubtedly true that in localities where artificial fertilizers can 
be readily procured, farming could be carried on successfully without 
the presence of any humus in the soil. This point has been proved 
not only on the small scale, by the experiments of Stceckhardt, Wolff, 
and many other observers, but by actual farming practice in Belgium.* 
But while it must be admitted, that, strictly speaking, the presence of 
humus in the soil cannot be accounted an indispensable condition for 
the growth of excellent crops, it is still true that most soils do contain 
more or less of it; that its nitrogeneous constituents are to a certain 
extent useful for the growth of plants; and that it is the farmer’s busi- 
ness to cultivate his land in such manner that the best possible eco- 
nomic use shall be made of each and all of its ingredients. 
Besides the familiar instances already cited of the growth of flower- 
ing-plants in pots filled with unmanured loam that is watered with 
rain-water, and of wild plants in the fields and forests that are sup- 
ported by the stores of nitrogenous (and other) matters that have 
accumulated in the earth through the decay of precedent vegetation, 
several other striking illustrations of the fact will be found on study- 
ing the farming practices of various countries and localities where 
special manures of one kind or another are habitually used with suc- 
cess. Thus, it has long been known, from the writings of Bobierre and 
of Malaguti, that there are certain districts of Trance, ‘and especially 
in Brittany, where the use of spent bone-black as a manure is attended 
with excellent results. Even fresh bone-black, and those kinds of 
waste bone-black that contain no nitrogen, produce useful effects in that 
region, especially when applied to land that has been newly broken up.f 
Since the use of spent bone-black by itself in this way, as a special 
manure, is peculiar to the agriculture of certain parts of France, and is 
a practice that has rarely, if ever, fourid favor elsewhere, it is but nat- 
ural to inquire what circumstances are there peculiar to that region 
which can account for a custom so extraordinary? ‘The explanation 
* See Steeckhardt’s “ Chemische Ackersmann,” 1856, 2. pp. 41-54. Compare 
ibid., 1861, 7. 193, and the well-known field experiments of Messrs. Lawes & 
Gilbert. 
t See, for example, the recent edition of Bobierre’s ‘‘Lecons de Chimie 
Agricole, Paris, 1872, the 11th Lecture, and elsewhere, as well as the earlier 
writings of that chemist, and the printed reports of Malaguti’s Lectures at 
Rennes. 
