286 PLINY'S NATURAL HISTORY. [Book XV. 



left with the am urea and the pulp, 55 or, in other words, the flesh 

 of the olive that forms the residue and becomes the dregs. 

 For this reason, he recommends that the oil should be poured 

 off several times in the day, and then put into vessels or caul- 

 drons S6 of lead, for copper vessels will spoil it, he says. All 

 these operations, however, should be carried on with presses 

 heated and tightly closed, 57 and exposed to the air as little as 

 possible — for which reason he recommends that wood should 

 never be cut there, the most convenient fuel for the fires being 

 the stones of the berries. From the cauldron the oil should 

 be poured into vats, 5b in order that the pulp and the amurca 

 may be disengaged in a solidified form : to effect which object 

 the vessels should be changed as often as convenient, while at 

 the same time the osier baskets should be carefully cleaned with 

 a sponge, that the oil may run out in as clean and pure a state 

 as possible. 



In later times, the plan has been adopted of invariably 

 crushing the olives in boiling water, and at once putting thern 

 whole in the press — a method of effectually extracting the 

 amurca — and then, after crushing them in the oil-press, sub- 

 jecting them to pressure once more. It is recommended, that 

 not more than one hundred modii should be pressed at one 

 time : the name given to this quantity is " factus," 59 while the 

 oil that flows out at the first pressure is called the " flos." 60 

 Four men, working at two presses day and night, ought to 

 be able to press out three factuses of olives. 



CHAP. 7. (7.) — FORTY -EIGHT VARIETIES OF ARTIFICIAL OILS. THE 

 CiCUS-TREE OR CROTON, OK SILI, OR SESAMUM. 



In those times artificial oils had not been introduced, ancl 



55 " Fracibus." The opinion of Pliny, that olives deteriorate by being left 

 in the store-room, is considered to be well founded ; the olives being apt 

 to ferment, to the deterioration of the oil : at the same time, he is wrong 

 in supposing that the amount of oil diminishes by keeping the berries. 



» 6 " Cortinas." If we may j udge from the name, these vessels were three- 

 footed, like a tripod. 



51 There are no good grounds for this recommendation, which is based 

 on the erroneous supposition that heat increases the oil in the berry. The 

 free circulation of the air also ought not to be restricted, as _ nothing is 

 gained by it. In general, the method of extracting the oil is the same 

 with the moderns as with the ancients, though these last did not employ 

 the aid of boiling water. 51 Liibra. 



^ A " making," or " batch." cu Or " flower." 



