The prices of Smyrna valonias are from L13 to L14 per ton; those of picked Morea, L10 per ton.  The duty received on valonias imported in 1842 was about L4,000.

The annual produce is sufficient to meet the wants of all Europe.  It can be had in Turkey to any extent and at all periods.  Many cargoes are sent to Dublin, and the German markets.  A little valonia is exported from Manila, the shipments having been about 150 tons per annum.

Camata and Camatina are two varieties of very young valonias, which are found more valuable for some processes of tanning than the common kinds.

Extensive as has been the enumeration of the vegetable substances used in the various branches of art and manufacture which have formed the principal subjects of this section, it is probable that with the progress of knowledge, of scientific experiment, and of investigation into the properties of given commodities, the list will be indefinitely increased.  What I have stated will suffice to give the reader an idea of the surprising variety of sources from which we receive the raw materials which enable us to perfect some of the most elegant processes of manufacturing skill and ingenuity, and will further afford some criterion—­though, of course, not a perfect one—­for estimating the relative importance of the tanning and dyeing substances.

SECTION V.

OLEAGINOUS PLANTS, AND THOSE YIELDING FIXED OR ESSENTIAL OILS.

Few cultivators are probably aware of the great importance of oil to this country, and the number of purposes for which it is employed in the arts and manufactures.  It is extensively used for candle and soap making, for burning in lamps, for diminishing friction in machinery of all kinds, and especially for locomotives—­in wool-dressing, in the manufacture of paints and varnishes, as an article of food, for medicinal purposes, &c.

So important are vegetable oils deemed, that the Society of Arts, in its prize list for 1851, offered gold medals for the importation or introduction into this country of any new plants or trees from China, India, or elsewhere, producing oils or fatty substances, such as can be used as food, or are applicable to manufacturing purposes; and also to the person who shall manufacture and import the finest specimen of oil, not less than ten gallons, the produce of olives grown in any British colony in Africa or Australasia.

The time of burning of equal quantities of the following oils has been found to be—­

Hours. 
Oil of poppy                        14
"    sunflower                    13
"    rape                         11
"    mustard                      111/2
"    flax seed                    10
"    gold of pleasure
(Camelina sativa)       91/2
"    olives                        9
"    hemp seed                     8
"    tallow                       101/2

FOREIGN VEGETABLE OILS IMPORTED.