Minor Cereals, Oil-bearing and Leguminous Seeds. 149 



of much importance in foreign countries are little known here. 

 Flax grain carries a considerable quantity of protein with an 

 excess of oil. There is no starch in well-matured flax seeds. On 

 account of the high commercial value of the oil, flax seed is rarely- 

 used as a feed. 



At the Iowa Station, ^ Wilson fed ground flax seed with skim 

 milk to calves with excellent results. (5J9) When flax seed was 

 fed to cows at the rate of eight pounds per head daily, no ill 

 results followed such heavy feeding. Some feeders claim that 

 flax seed should only be fed in a very limited quantity, since it 

 contains a cathartic principle. 



200. Oil cake and oil meal. — At the oil mills, after crushing the 

 seeds, the oil is removed by one of two processes. In the first the 

 crushed seed is heated and placed between cloths or in sacks which 

 are piled one on another and the mass subjected to hydraulic pres- 

 sure, to extract the oil. The residue after pressure, stripped of the 

 wrappings, appears as hard slabs or cakes, about an inch thick by 

 one foot in width and two in length. These slabs constitute the 

 oil cakes of commerce, and in the entire form are shipped abroad 

 for use by farmers in other countries. The unbroken cake is 

 preferred for shipping, as it is the most condensed, and because 

 the foreign feeder, suspicious of adulteration, knows that such 

 cakes are always as pure as the seed from which they were pro- 

 duced. When required for feeding, the cake is reduced to the 

 size of small hickory nuts or hazel nuts in a mill, the material 

 being known as ''nut cake." In this country the cake is usually 

 ground to a meal at the factory and is then shipped in bags. 

 Where the oil is secured by direct pressure from the ground flax 

 seed as described above, the by-product is known as ' ' old process ' ' 

 cake or oil meal. 



201. New-process oil meal. — In the manufacture of new-process 

 on meal, according to Woll, ^ the seed is crushed and heated to 

 165 ° Fahr. , as in the production of old-process meal. The crushed 

 mass while warm is placed in large vertical cylinders or percola- 

 tors, and over it naphtha, a volatile petroleum compound, is 



1 Buls. 14, 16, 19, 35. 

 * Kept. Wis. Sta. 1895. 



