336 Chemical Changes in the Fermentation of Dune/. 
Mulder's formula for albumen is C^mt Hsio? ^so? Oiso ^21 
Payen's for lignine (straw) is Cgj, Hg,, Og,,, and these two 
formulae represent the principal portion of the organic matter 
which we put to ferment. What wonder then at the escape of 
carbon which went far to swell the loss sustained by the manure 
above mentioned, and of all other fermented under similar 
circumstances ? VVlien the offensive odours of putrefaction 
can be derived from substances existing in such small quan- 
tities as sulphur and phosphorus, and when the proportion- 
ately scarce nitrogen is given off in such abundance as am- 
monia that a vessel of hydrochloric or dilute sulphuric acid placed 
upon a manure heap or in a necessary is soon converted into an 
ammoniacal salt, there can be no difficulty in apprehending the 
enormous quantity of carbon which is converted into a volatile 
oxide to unite with ammonia and rob the individual farmer to 
benefit we know not whom. Assuredly Liebig's views in regard 
to the sufficiency of the atmosphere to supply plants with organic 
matter when they are well supplied with inorganic matter by the 
soil will exempt him from a charge of leaning too much to the 
economy of our home-made manure. 1 et he writes thus : " In a 
scientific (practical ?) point of view it should be the care of the 
agriculturist so to employ all the substances containing a large 
proportion of nitrogen which his farm affords in the form of 
animal excrements that they shall serve as nutriment to his oion 
j)lauts. This will not be tlie case unless those substances are 
properly distributed upon his land. A heap of manure lying 
flask a strip of lead paper in such a manner that part of it shall hang down into 
the flask. The following changes will be observed to take place, more rapidly at 
a wami, more slowly at a cold temperature : — 
(a.) Bubbles of g;is escape from the glass tube into the second flask: they 
consist of carbonic acid (and some hydrogen) as may be seen by the 
turbidness which follows on the addition of lime-water. 
(b.) The lead paper is coloured dark — a sign of sulphuretted hydrogen being 
generated. 
(c.) A pungent smell of ammonia is evolved from the liquid standing over 
the gluten when it is heated with lime or potassa : consequently 
ammonia has also been formed. 
If we compare this process of decomposition with that which takes place on the 
putrefaction of non-nitrogenous substances we shall observe the following prin- 
cipal difference in the result: — On the piitrefarlion of albuminous substances their 
nitrogen and sulphur {and phosphorus) combine with hi/droc/en, forming ammonia and 
sulphuretted hi/drogni (and plwsphuretted hydrogen). These aeriform substances 
are the chief cause of the very disagreeable odour which is given ofi' during the 
decay or putrefaction of nitrogenous substances, for instance animal substances. 
During the further progress of this decomposition there is formed also as with 
ligneous fibre a brown substance resembling humus." 
I extract this because the simple experiment given is within the power and 
means of any farmer however poor or illiterate, and because it really brings before 
him in a comprehensible form changes which go on daily in his dung-heaps to his 
serious loss. The man who has but a cottage allotment may find both means and 
skill to do what is here directed. 
