in Acids,
Alcohol, and Ether._

Uric acid 21.14
Resin 1.11
Fatty acids 1.60
Nitrogenous and sulphurous organic substances 2.29
Calcium phosphate 18.22
Phosphate of iron 1.04
Silica .64
-----
46.04
-----

In the above analysis it will be noticed that none of the ammonia is
present as carbonate. In most samples, however, of Peruvian guano, the
ammonia in this form amounted to from 1 to 2 per cent. In the inferior
qualities, chiefly those which had been subjected to the action of
water, and consequently of fermentation, to a certain extent, this form
of ammonia was found to be most abundant. Such guanos were most liable
to loss of nitrogen by volatilisation.

The older Peruvian guano contained as high as 14 per cent of nitrogen
(equal to 17 per cent of ammonia), and of phosphoric acid 12 to 14 per
cent (equal to 26 to 28 per cent of phosphate of lime). It, however,
gradually deteriorated in quality as the deposits became worked out, the
percentage of nitrogen becoming year by year less, until latterly
Peruvian guano, as imported, contains only from 3 to 4 per cent of
nitrogen (equal to 4 to 5 per cent of ammonia). This guano is, however,
richer in phosphates, containing often 50 to 60 per cent of phosphate of
lime, and 3 to 4 per cent of potash.[192]

(_b_) OTHER NITROGENOUS GUANOS.

The guanos, other than those which come from Peru, are chiefly purely
phosphatic guanos, so that the term Peruvian has not unfrequently in the
past been used as a generic term synonymous with the term nitrogenous,
and consequently applied to all nitrogenous guanos independent of their
source. There are, however, a few deposits other than the Peruvian
which have yielded considerable quantities of valuable nitrogenous
guano. Of those, the richest in quality--in fact, the richest of any
deposits hitherto discovered--was the Angamos guano, which came from a
rocky promontory on the coast of Bolivia. The few samples of this which
have been analysed showed over 20 per cent of nitrogen. Unfortunately,
the deposit proved to be comparatively insignifica