Peruvian Guano. 
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Damaged Guano. 
The case is different with damaged or wet guano. Such guano 
is generally in an active state of decomposition, and loses the 
more ammonia the longer it is kept. When good gnano is mois- 
tened with water, it enters into an active fermentation in less 
than 24 hours, in consequence of which it rapidly loses ammonia. 
Care, therefore, should be taken not to expose guano to rain, and 
not to store it away on a damp floor or in an exposed shed. 
The peculiar smell of dry Peruvian guano, it has been observed 
already, is caused by a number of fatty acids derived from the 
fish-oil of the food of the guano-birds. There are, however, many 
persons who, on noticing the more or less powerful smell emanat- 
ing from guano, farmyard manure, compost-heaps, and similar mat- 
ters, have an indiscriminate apprehension of a loss of ammonia. 
In an active state of putrefaction refuse matters of that kind cer- 
tainly give off ammonia, but when the "process of putrefaction is 
effectually arrested by desiccation, the further evolution of am- 
monia ceases, and the disagreeable smell of the refuse matter, 
though not so pungent as before, still remains sufficiently unaltered 
to show that animal matters may smell strongly and yet not lose 
any ammonia. 
If any one doubts the truth of this assertion, let him drench 
a couple of ounces of Peruvian guano completely with dilute 
sulphuric acid, and he will find that the characteristic smell of 
the guano is not removed or weakened by the acid. If the 
smell were due to ammonia, the excess of acid would of course 
instantly saturate this volatile alkali, and destroy the smell. 
Guano soaked in oil of vitriol may be dried and heated for hours 
at a temperature not exceeding 212 3 Fahr. without losing its 
peculiar smell ; though it is hardly necessary to say that at that 
temperature ammonia cannot escape from a dry and very acid 
powder. 
Damaged and wet guano should either be applied to the land 
without delay, or if this is impossible, it should be dried before 
it is stored away. To this end the guano may be thinly spread 
on a dry floor and be mixed with gypsum or a similar drying 
material. If sand or peat-mould or charcoal-dust is used, it 
may be well to moisten it at the same time with some oil of 
vitriol diluted with an equal bulk of water, for the acid will fix 
the free ammonia, which in wet guano amounts to 1J to If per 
cent. 
The mixture may be exposed with advantage to direct sun- 
heat, or be submitted to a moderate artificial drying heat, and if 
heat cannot be applied conveniently, the moist guano-mixture 
should be turned over in a place exposed to a current of air. 
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