Being a
government monopoly, the price at which the agents are to sell here is
fixed in Peru, and that price may be easily known; therefore, if any
dealer offers you Peruvian guano at "a reduced price," you may be sure
the quality is reduced also. Remember, that the lowest price by the ship
load, it can be procured for of the agents in Baltimore or New York is
$46 per ton of 2240 lbs. To this, every fair, honest dealer, must add
freight, insurance and profit. Every man who sells without such
addition, you may be sure will make his profit by short weight or
adulteration.

The next best test is its appearance. Good Peruvian guano is an
impalpable powder, perfectly dry to the touch, of a uniform brownish
yellow color, with a strong smell, like that of spirits of hartshorn,
contained in ammoniacal smelling bottles. But the smell is no test; that
which smells strongest may be worst, as the ammonia may be disengaged by
moisture or by the addition of lime or salt.

_The adulteration of guano_ is carried to a great extent in England, and
probably will be in this country. The principal adulterations are made
by the addition of loam, marl, sand, plaster, old lime, ashes, chalk,
salt, moisture, and by mixture with other guano of a cheaper quality.
The farmer need not depend upon the assertion, "this is a genuine
article--here is the inspector's certificate." We would not give a straw
for a corn basket full of certificates of analysis. The buyer must
analyse for himself. Mr. Nesbit, analytical chemist, London, has just
published a pamphlet from which we have condensed some very plain,
short, simple rules for testing the quality of guano. As the
adulterating substances are generally heavier than the guano, they may
be detected by a comparison of weight and measure. To do this, get a
small glass tube closed at one end, and weigh accurately an ounce of
pure guano, put it in the tube and carefully mark the hight it
fills--try several samples--if there is any difference, mark it. Now
weigh an ounce from a sample adulterated with one fourth its bulk of any
or all the preceding list of articles used for that purpose, and you
will find the difference of bulk between that and the genuine, very
perceptible.

_Test by Burning._--Guano burnt to ashes at a red heat will leave an ash
of a pearly white appearance, not varying in weight from 30 to 35 per
cent. of the quantity burnt. If it is adulterated with marl, sand, clay,
&c., the ash wil