118 ECONOMICAL GEOLOGY. 



Journalj' Nov. 1853, the cost of making fifty tons of fish- 

 manure by Pettit's patent method is as follows : — 



100 tons fish, at £2 per ton ... . je200 



Sulphuric acid 17 10s. 



Labor 25 



Total £242 10s. 



" The cost of one ton is therefore £4 17s., not including 

 interest or capital invested, wear and tear, &c. The price 

 paid for fish is the chief expense of the manufacture ; and 

 when reduced one half or more, as it can be in some locali- 

 ties, we see how promising this manufacture is. It is to 

 be considered too, that the fresh fish yield, when steamed, 

 two and two and a half per cent, of oil, the value of which 

 must be deducted from the cost of the fish manure. 



" A company has recently been formed at Christiana, in 

 Norway, with the object of making fish manure. Samples 

 of their first products have been analyzed bj' Dr. Stock- 

 hardt, and contained about ten per cent, of nitrogen, and 

 eight per cent, of phosphates of lime and magnesia. 



"On the coast of the North Sea, in Oldenburgh, an 

 excellent manure is made from a kind of small sea crab 

 that is caught there in large quantities. The crabs are 

 simply dried and ground. . . . This manure, called Granat 

 Guano, from the name of the crab, contains 11.23 per cent, 

 of nitrogen, and 5.23 per cent, phosphates of lime and 

 magnesia." 



The amount of material which can be obtained from the 

 waters for the manufacture of manure, it is impossible to 

 estimate ; but the quantities of fish drawn from them, for 

 ordinary consumption, is enormous. Poole, in the " Statistics 



