The Conservation of Farm-yard Manure. 
835 
Of the various potash salts available, lcainit is best, on account 
of its composition as well as of its cheapness. About 2 lb. per 
head of stock should be daily sprinkled on the litter. 
In one experiment (made in the same way as those described with 
earth and gypsum) 6 tons of dung into which, by daily additions, 
about 5 cwt. of kainit had been introduced, lost, in six months’ fer- 
mentation in the heaps, absolutely no nitrogen, though 12 per cent, 
of the total dry matter had disappeared. A similar result was found 
in a like trial in which the dung was enriched by the addition of 
liquid manure. It is to be noted, however, that in the case of pre- 
servation with kainit the dung does not rot down in the same way 
as it does when preserved with earth, or with gypsum or superphos- 
phate. The straw remains almost intact — showing that the kainit 
has considerable antiseptic action, as well as a merely absorbing one. 
What considerations should guide the farmer in choosing which 
method to adopt 1 The answer is : 
“ If he wishes — for manuring strong, moisture-retaining soil — to 
prepare a manure very prompt and energetic in its action, but one 
which, on the other hand, will be the less rich in humus-forming, 
organic matter, he will give the preference to preservation by a layer 
of earth. 
“ If he seeks — simultaneously with having prompt manurial action 
— to introduce into the soil the greatest possible quantity of organic 
matter (as in the case of strong clays poor in humus), it is dung 
treated with phosphatic gypsum or superphosphate that will most 
completely comply with these conditions. 
“ But he may have to deal with light and very open soils, in which 
dung that had already undergone great alteration would too soon 
be consumed. He may wish to apply a manure, the decomposition 
of which shall be slow, and which, at the same time, shall introduce 
as much as possible of the organic matter that is so important for 
this class of soils. In this case the treatment of dung by potash salts 
is to be preferred to the previous methods. 
“ It is to be observed that strong lands ( terres fortes ) generally 
lack phosphates, and are nearly always sufficiently rich in potash ; 
while, on the other hand, this base is frequently deficient in light, 
calcareous, or sandy soils. From this point of view, of supplying to 
the soil additions of phosphoric acid or potash, the suggestions ( indi- 
cations ) l of Holdefleiss appear to be well justified.” 
So far M, Grandeau has quoted from the analytical investiga- 
tions of Holdefleiss, which, seeing the scale on which the experi- 
ments were made, should be sufficiently convincing. 
But more than analytical evidence is forthcoming. We have 
two series of field-experiments with dung variously treated, and not 
treated. These are sufficiently interesting to bear uncurtailed 
translation of M. Grandeau’s description of them : 
“ In order to complete these interesting studies, the Director of 
the Institute of Proskau has carried out two series of experiments, 
of which I will briefly show the main results. 
“ Plots of 9 ares (between and 1 of an acre) each were set 
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