274. BULLETIN OF THE BUSSEY INSTITUTION. 
of fixity of the nitrates, there is little doubt but that in a country sub- 
ject to heavy rains, nitrate of soda may often be found to be a less 
valuable fertilizer than an equivalent amount of fish-scrap, unless 
special care be taken to apply the nitrate by fractions at several dif- 
ferent periods. In case the soii happens to stand in special need of 
phosphoric acid, as appears to be the case in some of the cotton- 
growing regions of the South, the difficulty of deciding as to the 
merits of the several kinds of nitrogenous fertilizers, is of course 
greatly increased, inasmuch as experiments made to that end are com- 
plicated and obscured by the action of the phosphoric acid naturally 
contained in fish-scrap and other manures of animal origin. In any 
event, the question must be a difficult one to decide, because of the great 
influence that moisture exerts (see beyond, page 279) upon the activity 
of the animal manures. They might invariably give good results on 
fields or in districts where the lay of the land is such that the surface- 
soil is adequately moistened by emanations from the ground water, 
and might constantly fail upon fields so situated as to be of necessity 
often dry. 
The influence of climate upon the use of soil-nitrogen by plants has 
been well illustrated by the interesting researches of Stceckhardt and 
Peters* on the effect of high and low temperatures upon processes 
of disintegration and decay in the soil. These investigators filled two 
boxes, each with 50 German Ibs. (25 kilogrammes) of a mixture of 
river sand and a sandy loam that contained but little humus, and two 
other boxes with a mixture of similar sand and loam to which 10% 
of vegetable mould taken from a hollow beech-tree had been added. 
One box in each of the pairs had a jacket or water-back filled with 
water which could be heated to any desired temperature by means of a 
system of pipes through which hot water was made to circulate. ‘The 
boxes were of zinc, packed and sheathed without with non-conducting 
materials. All the boxes were placed on a scaffold outside a window, 
in a position tolerably well shielded from rain, and were exposed during 
three months to the summer weather of Tharand, near Dresden. But 
by means of the hot-water pipes, the temperature of the earth in the 
jacketed boxes was kept constantly 8° or 10° C. higher than that of 
* Stoeckhardt’s ““ Chemische Ackersmann,” 1864, 10. 82, and “‘ Die landwirth- 
schaftlichen Versuchs-Stationen,” 4 118. Compare ‘“‘ Chemische Ackersmann,” 
1863, 9. 81, and 1871, 17. 147. 
