THE YAM. 



263 



renders these caudles less biittle, witliout im- 

 parting to them any unpleasant smell, or mate- 

 rially impairing the intensity of the light. Ex- 

 cellent candles are also made from a mixture of 

 three parts of this wax and one part of common 

 bees' wax. A quantity of the wax of this palm 

 was sent to England from Rio de Janeiro, and 

 subjected to a chemical analysis by Mr Brande. 

 The result of these experiments was highly 

 satisfactory as to its efficiency as a substitute for 

 wax candles. We know not whether its em- 

 ployment for this purpose be still persevered in. 



The leaves are not the only useful part of the 

 camauba palm. The green fruit, after being 

 boiled in several waters, affords a nutritive food; 

 the pith of the stem of the young plants, after 

 being bruised in water, is likewise applied to the 

 same purpose. The kernel of the fruit, when 

 ripe, is covered with a layer of sweet pulp, and 

 this is found to be wholesome food for cattle. 

 The leaves make a very durable covering for 

 houses, and in such service will sustain every 

 vicissitude of weather for twenty years without 

 requiring to be renewed. The trunk of the tree 

 is a useful wood for building houses, making 

 fences, and a variety of other purposes. 



The Ceroxylon Andicola, another species of 

 palm, also yields a substance somewhat resem- 

 bling wax. This palm is a native of the Andes, 

 towering in majestic beauty on mountains which 

 rise many hundred toises above the level of the sea, 

 approaching even to the verge of perpetual snow. 

 Humboldt describes the tree as attaining to the 

 prodigious height of one hundred and sixty feet, 

 while it differs from all the other species of palms 

 in flourishing under a much colder temperature. 

 The trunk of the ceroxylon is covered with a 

 peculiar kind of varnish, possessing some of the 

 properties of wax. Vauquelin subjected this 

 product to chemical analysis, and found that it 

 contained two-thirds of resin and one-third of 

 wax, thus differing materially from the inflam- 

 mable substances obtained from the corypha. 



Elaiis Guineetisis. This palm gi-ows in vari- 

 ous parts of Africa. It grows best in shady 

 places, and attains the height of fifteen to six- 

 teen feet. The fruit resembles the stone of the 

 date. When ripe, this nut is heated by fermen- 

 tation, and then coarsely pulverized in hollow 

 cylinders, by which its oily matter is separated. 

 It is then macerated in hot water, when the oil 

 gradually collects on the surface, and cooling, 

 concretes into a thick unctuous cake, of a light 

 lemon colour, with little or no taste, but having 

 a rich perfume. At the ordinary temperature 

 of the air it is not a fluid oil. At 69° it 

 begins to be slightly opaque ; at 62° it is of the 

 consistence of honey ; at 45° it is proportionably 

 thicker, but still retains a degree of softness. It 

 is heavier than most of the other expressed oils. 

 The quantity of oil in these nuts is very con- 



siderable, one gallon of nuts usually producing a 

 quart of c il. This oil is used as butter by the 

 natives of the Gold Coast, entering into all their 

 culinary prepai-ations ; and when eaten fresh, is 

 a delicate and wholesome article of diet, differing 

 as much from the palm oil imported into Eng- 

 land, as fresh butter does from that which is ran- 

 cid. It is employed in this country to make a 

 soap, which bears the name of palm soap ; and 

 also enters into thfi composition of other articles 

 of perfumery. The quantity used for home con- 

 sumption in 1830 was 160,000 cwt. 



CHAP. XXIX. 



THE YAM, ARROW ROOT, AND ALLIACEOUS PLANiri. 



There are several plants belonging to the mo- 

 nocotylodonous division whose roots are service- 

 able to man as food, especially some of those 

 which possess a farinaceous or starchy substance. 

 Although none of these are equal in value to the 

 potato, which will be described afterwards, yet 

 there are a few which deserve notice as affording 

 a considerable quantity of a farina as pure aa 

 that derived from the cerealia. 



The Yam fdioscorca sciHva), belongs to the 

 class dicecia, and order liexandria of Linna?us. 

 It is an herbaceous climb- 

 ing plant, with a slender 

 stalk, growing to the heiglit 

 of about twenty feet. The 

 leaves have long foot stalks, 

 and are smooth and sharp 

 pointed. The flowers are 

 small spikes, arising from 

 the base of the leaf stalk. 

 The roots are flat, either 

 palmated, a, or irregular 

 shaped, J, about twelve 

 inches in diameter ; exter- 

 nally of a dark brown colour, approaching to 

 black ; internally white. 



The Winged Yam (dioscorea alata), is ano- 

 ther species frequently cultivated. Its roots are 

 much larger than the other, being frequently 

 three feet long, and weighing about thirty 

 pounds. 



It is supposed that the yam was originally a 

 native of the East Indies, and from thence was 

 conveyed to the West India islands by the ori- 

 ginal settlers, for it is no where found growing 

 in a natural state in these islands. On the Mala- 

 bar coast, and in the island of Ceylon, on the 

 contrary, it is a common indigenous plant, grow- 

 ing in the woods with great luxuriance. It is 

 extensively cultivated in the tropical parts of 

 the continents of Africa, Asia, and America, and 

 is there an excellent substitute for the potatoe. 



Yams. 



