326 Miscellaneous Intelligence. 



These narrow kilns admit of there being drawn out of them every day, if 

 fully employed, more than two-thirds, or nearly three-fourths, of what they 

 contain, of well burnt lime, and afford fully three of lime-shells* for one 

 measure of coal, when large circular kilns will not give out more than one- 

 half of their contents every day, and require nearly one of coal for every 

 two measures of lime burnt. In a country sale of lime, the quantity sold 

 every day is liable to great fluctuations, two or three cart-loads will only 

 be required from an establishment which, the day before, supplied forty; 

 and, as lime is known to be a commodity, when exposed to the action of the 

 air, which becomes more bulk and heavy, and in that state does not admit 

 of being' carried to a distance without, additional labour, it has been an ob- 

 ject of importance with me to find out a construction of a kiln which will 

 allow of lime being kept for several days without slaking, and at the same time 

 to prevent the fire escaping at the top of the kiln, if the kiln stands twenty- 

 four hours without being employed, especially during the autumn and win- 

 ter, when the air is cold and the nights long. I now employ kilns of an egg- 

 shape, and also oval. The oval-shaped kilns are divided by arches across 

 the kiln, descending four feet from the top. The object of the arches across 

 the kilns is to prevent the sides of the kiln falling in or contracting, and also 

 circular openings to be formed for feeding in the stone and coal at the 

 mouth of the kiln. Upon this plan, a kiln of any length might be construct- 

 ed with numerous round mouths. 



But it is to be understood, that in whatever construction of kiln lime is 

 burnt, the fuel required to burn limestone must vary according to the soft- 

 ness, or hardness, or density of the stone, and the quality or strength of the 

 coal used. The same measure of coal in Scotland called Chews, when em- 

 ployed, will burn a greater quantity of lime in a given time than the same 

 quantity or weight of what is called Small Coal, the chews or little pieces of 

 coal admitting the air to circulate more freely through the kiln.— Mr. Men- 

 teath in Quarterly Journal of Agriculture. 



On Oleaginous Plants.— Among the articles of vegetable food, the oils 

 which are extracted from plants afford one of the most valuable 1 ; nor are 

 they of less importance in affording ns light by their combustion. They are 

 employed also in a number of manufactures, such as soap, woollens, var- 

 nishes, and perfumery. There arc two kinds of vegetable oil, distinguished 

 by the name of fixed and volatile. The latter may be extracted from almost 

 every plant; but it is used only as a perfume or to flavour liqueurs, such as 

 the oil called Attar of Roses. These sweet-scented oils constitute the luxury 

 of the sense of smelling, but are frequently prejudicial, from their effect on 

 the nerves; and some of them are employed medicinally. But the essential 

 or volatile oils arc not those most deserving our attention; the fixed oils are 

 of much higher importance, and are extracted from a class of plants, hence 

 called oleaginous. The oil is expressed from the seed of all these plants ex- 

 cepting the olive, in which it is obtained from the pericarp. The greater 

 part of the seeds of oleaginous plants contain albumen, and it is from this 

 that the oil is obtained ; but when the seed has no albumen, as is the case 

 with the poppy, it is the embryo which furnishes the oil. In the family of 

 the Euphorbiacete, all of which have oleaginous seeds, the embryo is of a 

 venemous nature, and the oil extracted from it would be poisonous ; while 

 that expressed from the albumen of the same plant, situated contiguous to 

 the embryo, is perfectly innocent. Such is Bancul-nut (Alcuritvs Mo/nrca- 

 numj, which is remarkably mild, and is eaten by the inhabitants of the 

 Molucca Isles, as we eat hedge-nuts in Europe, while oil obtained from the 

 embryo is an acrid poison. The fixed oils obtained by cultivation may be 

 ranged under three beads: 1st, Olive-oil, the produce of warm climates; 2d, 

 Nut-oil, that of temperate climates; and, 3d, Oils obtained from the seeds 

 of oleaginous herbs. The olive-tree originally came from Syria. That plant, 

 as well as the vine, was brought to Marseilles by the Phocians ; and, at the I 

 present day, it is cultivated in all the shores of the Mediterranean. It is al 

 tree of very slow growth, but of long duration : it can support a tempera-l 

 ture as low as eight or ten degrees of Fahrenheit, provided the air be dry ;| 

 but, if accompanied with humidity, one or two degrees, below the freezing 



point, proves fatal. 



F ' v • 



* This means not shells, but the burnt rock composed of them.— Eds. 



