OILS 443 



cup-leathers. The upper part of rod x has a screw formed upon it at K 3 , which 

 passes through the boss D 1 and enters the boss N, in which a screw-thread is formed. 

 The boss, K, is provided with handles, p, by turning which the rod K may be raised or 

 lowered when required. E is a pipe, through which water may be injected into the 

 vessel A, by a force-pump, such as Is generally employed to work hydraulic presses, 

 s is a cock, whereby a portion of the contents of the vessel B may be run off, and the 

 pressure relieved when necessary. The two bosses, K 1 and K 2 , being of equal area, 

 whatever pressure may be exerted within the vessel B, it does not tend to raise or 

 lower the rod K ; but such pressure, acting on the cup-leathers, will keep the joint 

 tight, and prevent the matters under pressure from leaking out. After a certain 

 quantity of oil or oleaginous matters have been expressed from vegetable or animal 

 substances, the remaining portions which they contain are more difficult to obtain, 

 and we therefore treat the oil, in combination with the substances in which it is con- 

 tained, in the following manner: 



The aforesaid substances, after coming from the oil-press or mill, are mixed with 

 as much warm water, or water slightly impregnated with alkaline matter, as will 

 reduce them to a semi-fluid state. They are then to be operated on in the apparatus 

 last described. For this purpose the handles p p are turned round, and the boss x 2 

 withdrawn from its opening, while the boss K 2 , which is much longer, will still close 

 the lower aperture. The semi-fluid materials are then put into the basin B', and fall 

 from thence into the vessel B ; when it is fully charged, the rod K is again lowered 

 into the position shown in the figure. The communication with the hydraulic press- 

 pump is then made by means of a cock attached to the pump, from which the water 

 flows, through the pipe K, into the vessel B, and thus with a few strokes of the pump 

 the whole of the contents of the vessel B will be subjected to the requisite pressure. 

 An interval of a few minutes is then allowed for the combination of the oil and water, 

 and the cock s is then opened, and a small portion of the fluid contents of the vessel 

 allowed to escape into the cistern. The pressure being thus relieved, the handles p P 

 are to be again turned so as to lift the rod K sufficiently high to withdraw the boss K 2 

 from the lower opening ; the contents of the vessel B will then flow out into the 

 cistern A, and the boss K 2 , being again lowered so as to close the lower aperture, 

 the refilling of the vessel may take place for another operation. The pressure thus 

 brought upon the mixture of oleaginous matters and water will cause the oil therein 

 contained to mix with the water, and form a milky-looking fluid, from which the oil 

 may be afterwards separated from the water, either by repose in large vessels, or by 

 evaporating the water therefrom by heat. When the oil is to be used for soap- 

 making, and some other purposes, this combination of oil and water may be used 

 without such separation. When seed-oil is thus obtained, the mucilaginous matters 

 assist in combining these fluids. After the materials have been drawn off from the 

 cistern A, and passed through a strainer, the solid portions are to undergo another 

 pressing, in order to displace the remaining portion of their fluid contents. In some 

 cases it will be found advantageous to boil up the milky-looking fluid resulting from 

 the operation last described, in order to coagulate the albuminous portions, and other- 

 wise assist in the purification of the oil. 



The quantities of oil produced by the various seeds vary greatly, and also different 

 samples of the same kind of seed. 



The following notes of Mr. E. Woolsey, and his remarks upon the subject of seed- 

 crushing, will be valuable : 



'The chief point. of difference depends upon the quality of seed employed. Heavy 

 seed will yield most oil ; and seed ripened under a hot sun, and where the flax is not 

 gathered too green,, is the best. The weight of linseed varies from 48 Ibs. to 52 Ibs. 

 per imperial bushel ; probably a very fair aA'erage is 49 Ibs,, or 392 Ibs. per imperial 

 quarter. I inspected one of the seed-crusher's books, and the average of 15 trials of 

 a quarter each of different seeds in the season averaged 14 J gallons of 7i Ibs. each ; 

 say, 109 Ibs. of oil per quarter. The crusher, who uses only fie hydraulic press, and 

 one pressing, informed me that 



Archangel seed will yield from . . . 15 to 16 gals, (of 7| Ibs. each). 

 Best Odessa . ... . .18 and even 19 ,. 



Good crushing seed ...... 15- ,, ,, 



Low seed, sxich as weighs 48 Ibs. per bushel . 13-J- 



' The average of the seed he has worked, which he represents to be of an inferior 

 quality, for the sake of its cheapness, yields 14 gallons per quarter. I had sonu 

 American seed which weighed 52J Ibs. per imperial bushel, ground and pressed 

 under my own observation, and it gave me 111 Ibs. of oil; that is to say, 418 Ibs. of 

 seed gave 111 Ibs. of oil = 26 P " d per cent. A friend of mine, who is a London crusher, 

 told me the oil varied according to the seed from 14 to 17 gallons ; and when you con- 



