436 



OILS 



1567 



Oil of Almonds is manufactured by agitating the kernels in bags, so as to separate 

 their brown skins, grinding them in a mill, then enclosing them in bags, and squeezing 

 them strongly between a series of cast-iron plates, in a hydraulic press ; without heat 

 at firsthand then between heated plates. The first oil is the purest, and least apt to 

 become rancid. It should be refined by filtering through porous paper. Next to olive- 

 oil, this species is the most easy to saponify. Bitter almonds being cheaper than the 

 sweet are used in preference for obtaining this oil, and they afford an article equally 

 bland, wholesome, and inodorous. But a strongly-scented oil may be procured, accord- 

 ing to M. Planche, by macerating the almonds in hot water, so as to blanch them, 

 then drying them in a stove, and afterwards subjecting them to pressure. The volatile 

 oil of almonds is obtained by distilling the marc or bitter-almond cake along with 

 water. 



Linseed, Rapeseed, and Poppyseed Oils. The seeds of these, and other oleiferous 

 seeds, were formerly treated for the extraction of their oil, by pounding in hard wooden 

 mortars with pestles shod with iron, set in motion by cams driven by a shaft turned 

 with horse- or water-power ; then the triturated seed was put into woollen bags which 

 were wrapped up in hair-cloths, and squeezed between upright wedges in press-boxes 

 by the impulsion of vertical rams driven also by a cam mechanism. In the best mills 

 upon the old construction, the cakes obtained by this first wedge pressure, were thrown 

 upon the bed of an edge-mill, ground anew, and subjected to a second pressure, aided 

 by heat now, as in the first case. These mortars and press-boxes constitute what are 

 called Dutch mills. They are still in use both in'this country and on the Continent, 



and are by some persons thought pre- 

 ferable to the hydraulic presses. 



The roller-mill for merely bruising 

 the linseed, &c., previous to grinding 

 it under edge-stones and to heating and 

 crushing it in a Dutch or a hydraulic 

 oil-mill, is represented mfgs. 1567 and 

 15G8. The iron shaft, a, has a winch 

 at each end, with a heavy fly-wheel 

 upon the one of them, when the ma- 

 chine is to be worked by hand. Upon 

 the opposite end is a pulley, -with an 

 endless cord which passes round a 

 pulley on the end of the fluted roller, 

 b, and thereby drives it. This fluted 

 roller, b, lies across the hopper, c, and 

 by its agitation causes the seeds to 

 descend equally through the hopper, 

 between the crushing rollers, d, e. 

 Upon the shaft, a, there is also a pinion 

 which works into two toothed wheels 

 on the shafts of the crushing cylinders, 

 d and e, thus communicating to these 

 cylinders motion in opposite directions. 

 f, g, are two scraper-blades, which by 

 means of the two weights, h, A, hang- 

 ing upon levers, are pressed against 

 the surfaces of the cylinders, and re- 

 move any seed-cake from them. The 

 bruised seeds fall through the slit, f, 

 of the case, and are received into a 

 chest which stands upon the board, k. 



Machines of this kind are now usually 

 driven by steam-power. Hydraulic 

 presses have been of late years intro- 

 duced into many seed-oil mills in this 

 country; but it is still a matter of 

 dispute whether they or the old Dutch 

 oil-mill, with bags of seed compressed 

 between wedges, driven by cam-stamps, 

 bo the- preferable ; that is, afford the largest product of oil with the same expenditure 

 of capital and power. 



This bruising of the seed is merely a preparation for its proper grinding, under a 

 pair of heavy edge-stones, of granite, from 5 to 7 feet in diameter ; because unbruised 

 seed is apt to slide away before the vertical rolling-wheel, and thus escape trituration. 



