GUANO. 271 



the birds who caused the deposit were protected by severe laws. 

 and the value of the manure was fully understood. The amount 

 of the accumulations, considering the nature of the deposit, is 

 immense, being represented, by travellers, as from three to seven 

 hundred feet in depth. The number of birds is stated to be 

 almost beyond calculation ; and any person who will take the 

 trouble to read, in that delightful book, Wilson s Ornithology, 

 the accounts of the roosting-places of the passenger-pigeon in 

 some of the Western States of America, will readily confide in 

 well-authenticated accounts of the number of these birds, which 

 would otherwise be deemed egregious exaggerations. To the 

 gentlemen in England who are fond of what is termed a battue, 

 a voyage to the Pacific to shoot the guano birds would afford 

 excellent sport ; and if in such case they would bring back loads 

 of this valuable manure, it might not prove an unprofitable enter 

 prise, and they would perform a double work of conciliation to 

 the farmers. Their accounts of one or two days shooting, or 

 knocking down the birds with the butt-ends of their guns, 

 would be read here with the greatest avidity, and eclipse all 

 their former exploits of killing hundreds of game in a single day 

 where the beaters were employed to drive them directly under 

 the muzzles of their guns, and where occasionally they are 

 obliged to knock down a poacher instead of a penguin. 



These deposits are made in a climate where, for a considerable 

 part of the year, little rain falls, and where the intense heat of 

 the sun forms such a crust over the deposit, that it becomes 

 almost insoluble. Supposing a deposit to be made of two inches 

 a year, for three thousand years, this would give a depth of five 

 hundred feet; and therefore the report of the depth of these 

 deposits, though surprising, is by no means intrinsically incred 

 ible. The extraordinary effect of this manure is another remark 

 able circumstance. The dung of the domestic pigeon or fowl is 

 among the strongest used, but it is not so powerful as guano. 

 In the excrements of birds, the solid and liquid portions are 

 combined. This is one secret of their strength. In the case of 

 the guano birds, their food is wholly fish, and not, as with our 

 domestic birds, mainly farinaceous ; and therefore it abounds in 

 nitrogen, and in bony substances, or phosphates. 



The secret of the extraordinary success of this manure is not 

 yet solved, however nearly a solution may have been approx- 



