AGRICULTURAL BOTANY. 251 



palm, furnishes it in very large quantity. Various species of (Enocarpus, -which abound on 

 the Amazon anil Rio Negro, are oil-bearing. The oil procured from (Enocarpus batana, 

 which forms forests in the Rio Negro, is called batana-oil by the Indians, and resembles much 

 that procured from olives. Eaphua toldigera, the Inpati palm, has a very oleaginous fruit, 

 and its leaf-stalks can be used as flambeaux. Andirola-oil is the produce of Carapa gura- 

 nensis. Bertholletia excelsa, the Castanha or Tuna, is another oil-giving tree of the Amazon 

 district. 



Beech-oil. 



Among the various kinds of oil used in Northern Germany, especially the kingdom of 

 Hanover, for culinary purposes or as materials of combustion, that extracted from the nuts 

 of the beech (Tagus sylvatica, Linn.) is, on account of its numerous good qualities, de- 

 serving of notice. Beech-oil does not play a prominent part in commerce, nor is it likely to 

 do so, owing to the fact that it cannot be procured in large quantities ; the country-people 

 who collect the nuts, or who cause them to be collected, use the greater part of the oil ex- 

 tracted from them in their own households, and only dispose of the remaining fraction. This 

 is the reason why it is impossible to give even a rough estimate of the quantity annually 

 produced. About Hanover, the nuts are gathered towards the end of October or the begin- 

 ning of November ; this is done either by picking up by hand those which have fallen to the 

 ground, or by spreading out large sheets under the trees and beating the branches with 

 poles, so as to cause the nuts to separate from them. The latter pi-ocess appears, at first 

 sight, the least expensive; but as the good nuts have to be separated from the bad (abortive) 

 ones, it is found, on closer examination, to be just the contrary. In 1854, about twenty-five 

 pounds of nuts sold in Hanover for eighteenpence ; twenty-five pounds yield about five 

 pounds of oil, one pound selling for about sevenpence. The oil is of a pale-yellow color, 

 and has an extremely agreeable taste. It is often adulterated with walnut-oil ; the latter is 

 even sold as beech-oil, and that may account for the difference of opinion entertained re- 

 specting the quality of beech-oil. The towns-people use it chiefly as salad oil ; but the pea- 

 santry employ it generally as a substitute for butter, &c, and only when there has been a 

 good harvest of nuts, for burning in their lamps. The husks (epicarpia) are, after the oil 

 has beeu expressed, made into cakes about nine inches square and an inch and a half thick ; 

 these are used for combustibles, and not given, as some people imagine, as food to cattle. — 

 Hooker's Journal of Botany. 



Rapeseed-oil. 



The following information respecting the demand for oils, especially that expressed from 

 rapeseed, is derived from the last Report of the Lighthouse Board : — 



In 1841-42 the price of sperm-oil was $0.55 per gallon ; 

 " 1847-48 " " 1.07-18 " 



" 1851-52 « " 1.19-37 " 



" 1853-54 " " 1.38-75 " 



and the last purchase made by public contract for the Lighthouse establishment was at $1.58 

 for full-strained sperm-oil. 



The most respectable merchants and ship-owners engaged in the sperm-whale fishery are 

 of opinion that there will be a considerable advance upon the present price ($1.60 per gallon) 

 for winter oil during the present year, and that it will probably be as high as $2 per gallon 

 at no distant day. 



The rapid advance in the price of this essential article for lighthouse purposes is said to 

 be attributable to the limited and annually diminishing supply, and to the increased demand 

 for it for lubricating and manufacturing purposes in this country and in Great Britain. 

 Numerous experiments have been made to test the practicability of using lai'd-oil, cotton- 

 seed-oil, and some of the various patent oils, both animal and vegetable, in lighthouses ; but 

 it is believed that, with the exception of the colza or rapeseed-oil, none of them are suited to 

 purposes of lighthouse illumination. The lighthouses and lightvessels on the continent of 

 Europe and in Great Britain, with few exceptions, are now illuminated by the colza or rape- 



