THE OLIVE 143 



on the liquid becomes tinged with purple from the coloring matter 

 in the berrv. 



Admitting the definition as correct, we should have five possible 

 qualities of palatable oil, and two, suitable only for manufacturing 

 purposes. It is unnecessary to say that Virgin oil as defined above 

 is not an article of trade. A little is probably made on large es- 

 tates, for the proprietors, and for their friends consumption, nor is 

 it necessary to say, that the four possible edible oils are reduced to 

 two or three. 



If a run is made without water, the second run will probably be 

 made with hot water, or two runs without water and then the hot 

 water or with cold water at once, and then hot water. Cold water is 

 not injurious, but oil gathered by the hot water process is not as fine, 

 and does not keep as well as that expressed without water or with the 

 use of the cold. Extreme heat is dangerous to oil at all stages of ex- 

 pression and storage; and for this reason Italians doubt the safety of 

 artificial drying even where they consider drying necessary or advanta- 

 geous. After the expression of the oil, it separates from the water 

 and small particles of the berry which have passed the sacks or 

 cage, and rises to the surface, when it is carefully skimmed off and 

 placed in other vessels to settle; thence drawn oflF again from the 

 surface, and clarified by being passed through a layer of filtering 

 cotton, filtering paper, or even bone charcoal. It is then fit to place 

 in the storage receptacle. During the process of crushing, pressing, 

 depositing and clarifying, too extreme cold chills the oil and checks 

 its flow and clarification, and in cold weather it is desirable to have 

 moderate artificial heat in the mill. When clarified, the oil should 

 be put in a cool place, and in cool receivers, of which tanks of tiles, 

 brick lined with marble, or glass, and the Italian glazed terra-cotta 

 lined tanks are the best. The Italians use wooden tanks lined with 

 tin and also brick tanks lined with a fine cement. Wood is not 

 desirable, the oil wdiich soaks into it is liable to turn rancid. Again 

 wood alone, lacks the coolness required, at least in an Italian sum- 



