98 



has squeezed the marc enough, and got as much out of it 

 as he can, that time. The oil thus expressed runs out 

 at a hole in the bottom, the bags are taken from the 

 ir-queezing-box, and from each of them is removed a 

 cake. 



But whatever may be the mode of milling, it takes at 

 least two acts of pressure to obtain a respectable yield of 

 oil. The cakes are again put into the mortar, and are 

 once more pounded as fine as may be. They are again 

 carried into the back apartment after their second re- 

 duction to a pasty state ; but before a second entrance 

 into the bags they are gently warmed over a slow fire, 

 in a flat and shallow warming-pan of iron. Inside the 

 pan, a piece of machinery connected with the mill- work, 

 and crookedly resembling the hand of a clock which in- 

 dicates the hours only, keeps moving slowly round- and 

 round, stirring the powdered oil-cake, and preventing it 

 from burning. The powder, when sufficiently warmed 

 throughout, is again bagged, wedged, and squeezed, till 

 it has parted with every drop of oil that can thus be ex- 

 tracted from it. The cakes are then mostly set aside, 

 and put up to dry, to be subsequently sold to fatten 

 cattle at home or abroad. In Flanders (both French 

 and Belgian), a large amount of oil-cake is returned to 

 the land, either in the shape of coarse powder, or after 

 soaking and steeping in the liquid manure tanks, with 

 which fertilizer it is made to combine. 



The heat employed to aid in liberating the oil from the 

 seeds containing it, also sets loose some other particles, 

 which, either for medicinal or culinary purposes, it is de- 

 sirable to get rid of; hence the preference given to "cold- 

 drawn castor oil." The final treatment, therefore, of vege- 

 table oil is its clarification, which is more generally perfor- 

 med by the oil-merchant than the miller. Seed oils, on 

 escaping from the press, always contain a portion of 

 mucilage, colouring matter, and resinous principles, 

 which are all native to and latent in the seed, and which 

 cause it to have a particular smell, taste, and appearance. 

 They are partially removed by keeping the oil for a con- 



