316 Animal Excrements. 
than to form an opinion of the value of guano by its smell or ap- 
pearance. Suppose the farmer possessed of a genuine sample, he 
will much " improve its quality by the addition of a small quantity 
of gypsum or charcoal, both of which substances have the property 
of absorbing free ammoniacal gas." 
Our author states as his opinion, that it is impossible that the 
aquatic birds of the present geological period can have produced 
the immense deposits found on the shores of Peru; there is, there- 
fore, every reason to believe them to be capriolites, or fossil ex- 
crements of antediluvian birds." Though we believe this subject 
has never been carefully examined, yet it seems likely that Girar- 
din is mistaken in the above assertion. Withoutseeing the place, 
we can form no idea of the countless myriads of birds which flock 
to these shores century after century. Besides, seals have been 
found imbedded in the guano of the same form as those which 
still exist in the adjoining seas; and in one case a human mummy 
has been found. — {^American Jour, of Science.) We are not 
without hope that the fossil animal excrements, or capriolites, will 
ultimately be used in agriculture. They are known to exist in 
considerable quantities in some parts of England, especially oolite, 
and contain the same chemical substances as the modern deposits. 
It has even been shown that urea exists in some of these caprio- 
lites; thus making them agree to an unexpected extent, with the 
dung of birds now living. — (Jour. Geological Society.) We 
know of few more interesting discoveries in modern chemistry and 
geology than the above, except that of the little aquatic animal 
yielding sapia in a fossil state, when it had been entombed for 
countless ages, and yet furnished sufficient of its own peculiar 
color as to enable the artist to paint its own likeness. The En- 
glish farmer will be surprised to learn, that in Flanders it is cus- 
tomary to pay j£4 per annum for the dung of 600 to 650 pigeons. 
The following analysis of the dung of pigeons and barn-door 
fowls will give an idea of their comparative value: 
Pigeons. Poultry. 
Water 79-00 72-00 
Azotised vegetable matter 18*11 16*20 
Saline, or mineral do — --- 2*28 5-24 
Insolvent matter, sand, &c. 0-61 5*66 
100-00 100*00 
Both these substances have been applied with success to clover 
when mixed with charcoal." 
Johnston, in his Agricultural Chemistry, has given a recipe for 
artificial guano, which has not, however, as yet, fulfilled every 
expectation. But we doubt not, in a few years, to see that sub- 
stance successfully imitated. 
