54 FERTILITY AND FERTILIZI^R HINTS 



and its value depends a great deal on its nitrogen content. It is 

 suitable for crops having a long growing season. 



About 1,000,000 tons of tankage and dried blood are produced 

 annually. 



Azotin, meat meal, flesh meal, dried meat, animal matter and 

 ammonite are practically the same product, but are by-products 

 from different manufacturing establishments. Most of this prod- 

 uct comes from the slaughtering houses and beef extract factor- 

 ies. It is a rich organic fertilizer containing about 13 per cent, 

 nitrogen, but it may run higher or lower than this depending 

 upon its purity. This product is made up generally of the flesh 

 refuse of dead animals from which the fat has been extracted 

 and the remains dried and ground. It is different from tankage 

 because it does not contain bones. 



Steamed horn and hoof meal averages about 12 to 15 per cent, 

 nitrogen and is principally marketed by the large packing houses. 

 The choice horns and hoofs are sold for the manufacture of 

 buttons, combs, and novelties, and the imperfect and off-col- 

 ored horns and hoofs are treated with steam, under high pres- 

 sure, which renders the nitrogen more available and permits of 

 the product being ground to a fine powder. Horn and hoof 

 meal was not formerly thought much of, but since it has been 

 subjected to superheated steam the product has been much 

 sought after by the manufacturers of fertilizers. It is produced 

 only in limited quantities and is not as valuable as dried blood, 

 but has a fairly high degree of availability, according to recent 

 investigations.* 



Dry Ground Fish. — This is also called fish scrap and fish guano 

 and has a yellow color. It is obtained principally from canning 

 factories where the refuse as bones, skin, heads, fins, tails, in- 

 testines, etc., of edible fish are saved, dried and ground. Estab- 

 lishments expressing oil and manufacturing glue from inedible 

 fish as Menhaden, furnish a considerable supply. The average 

 annual catch of Menhaden is about 600,000,000 fish, which pro- 

 duce 70,000 tons of fish scrap and 35,000 barrels of oil. Thirty 

 factories with 70 steamers are engaged in this industry and the 



