MAI. 



MAL 



MAG^£SIU.M. The metallic ba- 

 sis of magnesia ; it is bright and 

 white like silver : symbol Mg. ; eq. 

 1269. 



MAGNETIC NEEDLE. A small 

 bar or needle of steel, fully magnet- 

 ized, and suspended or supported so 

 as to move freely over a card divided 

 into the points of the compass. It is 

 much used by surveyors to take down 

 the bearing of the fences and other 

 lines of a farm. 



MAGNETISM. The electric fluid 

 manifesting itself on a metallic body : 

 iron, cobalt, and nickel are the only 

 magnetic metals. 



MAGNOLIA. A genus of hand- 

 some liowering trees. There are 

 about 15 native species, of which M. 

 grandifolia, rising 90 feet, is the no- 

 blest. The M. macrophylla, though a 

 small tree, produces magnificent flow- 

 ers and leaves. The M. glauca is a 

 favourite in Northern shrubberies. 



MAHALEB. A species of plum 

 or cherry, used as a grafting stock : 

 the fruit affords a violet dye. 



MAIDEN HAIR. Ferns of the 

 genus Adianlum, a beautiful race : 

 the sirup of capillaire is supposed to 

 be made from a species. 



MAIZE. Indian corn. See Corn. 

 MALACODERMS (from /za/.a«of, 

 soft, and Sepua, skin). A tribe of soft- 

 skinned, serricorn beetles. 



MALARIA. The poisonous exha- 

 lations of stagnant marshes and low 

 new lands, producing bilious fever, 

 agues, and plagues. It is most ac- 

 tive at nightfall and during night, and 

 may be partially avoided by remain- 

 ing at home at these times, and ta- 

 king care to keep the premises warm 

 and dry : the spring and autumn are 

 the worst seasons. Strangers are 

 more liable to the influence of mala- 

 ria than natives. 



MALE FLOWERS. Such as have 

 stamens only, and no ovary or swell- 

 ing under the petals. 



MALIC ACID. The sour princi- 

 ple of apples, oranges, and numerous 

 fruits ; when pure, it is intensely sour 

 and crystalline ; combines with ox- 

 ides to form mallates : formula Cs H4 

 O3 + 2 H O : it is bibasic. By heat- 

 476 



1 ing the hydrated acid, it is converted 

 into maleic acid and fumaric acid. 



MALIGNANT. Rapidly fatal, poi- 

 I sonous. 



MALLEABILITY. Tlie property 

 of being extended by hammering, as 

 in the case of gold, copper, silver, 

 platina, iron, &c. 



MALLENDERS. A disease pro- 

 duced in horses by neglect and over 

 work, in which chaps or cracks ap- 

 pear on the inside of the fore legs, 

 near the knees, attended by a dis- 

 charge of a red ichorous fluid ; the 

 sores should be washed with soap 

 and water, and kept clean ; after- 

 ward they are to be dressed with an 

 ointment containing blue vitriol : the 

 animal is also to be kept quiet and 

 purged. 



M ALLOW. The genus Malva ; 

 plants usually with perennial roots, 

 and abounding in mucilage : they are 

 eaten by all animals. 



MAL T. Barley which has been 

 prepared or malted, by which sprout- 

 ing is induced, and the grain becomes 

 much sweeter. 



MALTING. The process consists 

 of three steps : 1st, steeping-. The 

 good barley is thrown into large 

 wooden cisterns, and covered with 

 water a few inches, being left for 

 48 to 60 hours, or until the grains 

 are soft, but do not yield milk on 

 pressure. 2d, couching. The steeped 

 grain is removed to a floor of stone, 

 and piled in heaps 12 to 16 inches 

 high ; here it first dries, and then 

 heats : roots begin to appear as the 

 heat advances; the couch is spread 

 and made thinner : the time required 

 is from 16 to 20 days, at a tempera- 

 ture ofGO- Fahrenheit. Indry weath- 

 er, the couch is watered when too 

 dry. 3d, kiln-drying. As soon as the 

 barley is sufficiently germinated and 

 become dry, it is carried to the kiln 

 to destroy the vegetative power and 

 secure the sugar formed. It is here 

 laid three or four inches deep, and 

 kept at 100- Fahrenheit, till all the 

 moisture is driven off, the malt being 

 repeatedly turned. When nearly dry, 

 the heat is raised to 160^ Fahren- 

 heit, until the grains become coloured 



