FISH GUANO IN EUROPE. 319 



on account of overproduction of home-made fertilizers ob- 

 tained from suitable home resources. 



Millions of dollars are annually sent abroad still, for the 

 importation of materials, which, in their crude form, are by no 

 means better than what we have in abundance at home. 



The manufocture of fertilizers has become in the same 

 degree an art, as agriculture itself has justly assumed the 

 claim of being a science. 



The production of fish guano, although respectable already, 

 as far as quantity is concerned, is thus far but incidental to 

 the menhaden fish-renderiug industry. 



It remains still an open question whether our resources for 

 the manufacture of fish guano do not extend beyond that 

 branch of industry. 



To furnish some material for consideration resfarding that 

 important topic, I propose to close this statement with a short 

 sketch of the history and the present condition of the manu- 

 facture of fish guano in Europe. 



At certain periods of the year, there are noticed along the 

 coast of Sussex, Kent and Essex counties, in England, large 

 quantities of little herrings (Clupea sjjrattus) which for genera- 

 tions have been used by farmers in that vicinity for fertilizing 

 purposes. Messrs. Pettit and Green secured, in 1851-52, 

 patents for the manufacture of fish guano from these fishes. 

 Thompson and Way, who analyzed their product at difierent 

 times, state the percentage of nitrogen respectively at 11.5 

 per cent, and 13.83 per cent. 



The following course, it is stated, was adopted to produce 

 that guano : the fishes are cut fine by suitable machines, 

 after which they are treated with a few percentages of sul- 

 phuric acid, and subsequently subjected to the efficient action 

 of centrifugal apparatus for the removal of moisture. The pul- 

 verulent mass resulting was subsequently dried under stirring 

 with rakes upon a heated surface, and afterwards ground into 

 a uniform fine powder. A. Stockhardt, in whose labora- 

 tory the changes which fresh fish undergoes by steaming — 

 the usual treatment applied in our fish-rendering establish- 

 ments — have been carefully studied, found that 100 parts of 

 common herrings, subjected for one hour to the action of 

 steam, furnished ultimately 24.6 parts of perfectly dry guano. 



