366 OSERVATIONS ON GUANO 
is the custom in Peru, when it is applied, to 
irrigate the land immediately. 
Another course of failure is its adulteration 
by unprincipled dealers. An article has been 
sold for it, which did not contain 20 per cent of 
genuine Guano. A deceitful or false analysis 
has procured the sale of a cargo of it at a high 
price, and Dr. Ure states that when it came under 
his cognizance in consequence of having been 
employed professionally to analyze the identical 
cargo, he found the Guano to be nearly rotten 
and effete. 
It is probable, from the extensive use now 
being made of Guano, that at a period not very 
distant, its supply may be, either exhausted, or 
much limited in quantity. In the Liverpool 
Mercury, of November 15th, it is stated, that 
400 sail of vessels were then at Ichaboe, and that 
several had returned home without cargoes. This 
is worthy the attention of practical chemists, for 
if artificial manures can be found which will 
afford the farmer a cheap and permanent supply 
of their substances, which will give to his fields 
an increase of fertility, he will be rendered inde- 
pendent of the precarious supply obtained from 
