NITROGENOUS MANURES 125 



ter-houses is sometimes kept separate from the tank- 

 age and sold as flesh meal, the fat and gelatin being 

 first removed and used for the manufacture of glue and 

 soap. Flesh meal is variable in composition and may 

 be very slow in decomposing. It contains from 4 to 

 8 per cent, or more of nitrogen with an appreciable 

 amount of phosphoric acid. Occasionally it is used 

 for feeding poultry and hogs, and cattle to a limited 

 extent. When thus used the fertilizer value of the 

 dung is nearly equivalent to the original value of the 

 meal. 



156. Fish Scrap. The flesh of fish is very rich in 

 nitrogen. 49 The offal parts, as heads, fins, tails and in- 

 testines, are dried and prepared as a fertilizer. Some 

 species of fish which are not edible are caught in large 

 numbers to be used for this purpose. In sea-coast 

 regions fish fertilizer is one of the cheapest and best of 

 the nitrogenous manures. It is richer in nitrogen 

 than tankage or flesh meal, and in many cases equal 

 to dried blood. It readily undergoes nitrification and 

 is a quick-acting fertilizer. 



157. Seed Residues. Many seeds, as cottonseed 

 and flaxseed, are exceeding rich in nitrogen. When 

 the oil has been removed, the flaxseed and cottonseed 

 cake are proportionally richer in nitrogen than the 

 original seed. This cake is usually sold as cattle 

 food, but occasionally is used as fertilizer. Cotton- 

 seed cake contains from 6 to 7 per cent, of nitro- 

 gen, and compares fairly well in nitrogen content with 

 animal bodies. Cottonseed cake and meal are not so 

 quick-acting as dried blood, but when used in south- 



