LAC 



LAK 



consisting almost wholly of alumina, 

 saturated with carhonic acid. 



LACCIC ACID. An acid obtained 

 from stick-lac, forming salts called lac- 

 cates. 



LACCIN. A principle discovered in 

 lac, intermediate between wax and resin. 



LACE'RTA. The Lizard; a modern 

 northern constellation, consisting of six- 

 teen stars. It is surrounded by Andro- 

 meda, Cepheus, Cygnus, and Pegasus. 



LACERTI'NID^ {lacertus, a lizard). 

 A family of Saurian reptiles, including 

 the common lizards of this country, and 

 most of the Saurians of active habits. 

 They are characterized by their small 

 head, thick neck, and long, slender, 

 forkerl tongue. 



LACI'NIATED {lacinia, the fringe of 

 a garment). A term applied, in Botany, 

 to those leaves which are divided by 

 deep, taper-pointed incisions. Such 

 leaves are also said to be slashed, decom- 

 posed, or multifid. The inflexed point 

 of the umbelliferous petal is called the 

 lacinula. 



LA'CQUER. A solution of shell-lac 

 in alcohol. 



LA'CTEALS {lac, lactis, milk). Mi- 

 nute vessels which, in the animal eco- 

 nomy, absorb, or take up, the chyle, or 

 milk-like fluid, from the alimentary canal. 

 See Absorption. 



LACTIC ACID {lac, lactic, milk). 

 An acid generated whenever milk, and 

 perhaps most animal fluids, become spon- 

 taneously sour, or when the juice of beet- 

 root is preserved for some months at a 

 high temperature. Its salts are called 

 lactates. 



LA'CTINE {lac, milk). Saccholactin. 

 Sugar of milk ; obtained by evaporating 

 the whey of milk to crystallization, and 

 purifying the first product by animal 

 charcoal and a second crystallization. 



LACTO'METER {lac, lactis, milk, 

 /u^rpoi/, a measure). A graduated glass 

 tube, for ascertaining the relative quan- 

 tity of cream afforded by milk. A more 

 correct term would be galactometer. 



LACTU'CIC ACID. An acid dis- 

 covered in the juice of the lactuca virosa, 

 or wild lettuce. 



LACU'N^ {lacus, a lake). A term 

 applied by Link to the air-cells which 

 occur in the tissue of plants. In lichens, 

 they are the small hollows or pits which 

 occur on the upper surface of the thallus ; 

 and hence the term lacunose is applied to 

 a body which has large deep lacunae or 

 depressions on the surface. 

 190 



LACU'STRINE {lacus, a lake). Be- 

 longing to a lake. A lacustrine deposit 

 consists of alluvial matter carried down 

 by rivers and deposited at the bottom of 

 lakes. 



LiEMODI'PODA {\aifx6^, the throat, 

 7r6<5e9, feet). A group of crustaceous 

 animals, which have the anterior pair of 

 feet attached to the cephalic segment ; 

 they have no post-abdominal branchiae ; 

 the eyes are sessile, and the mandibles 

 without palpi.' A characteristic example 

 is found in the cyamus, commonly called 

 the whale-louse, from its infesting the 

 cetacea as a parasite. 



LAGOON or LAGUNE. An extensive 

 sheet of shallow water, formed either by 

 the encroachment of the sea or rivers 

 upon the land, or by the separation of a 

 portion of the sea by the intervention of 

 a bank. Thus, there are fluvial and 

 marine lagunes. 



LA'GRlIDJi:. A family of coleopte- 

 rous insects, of the section Heteromera, 

 named from the genus Lagria, one spe- 

 cies of which is indigenous in this coun- 

 try. 



LAKE. An insoluble compound, 

 formed by precipitating colouring matter 

 with an earth or oxide. The principal 

 lakes are carmine, obtained from cochi- 

 neal, by precipitation with Roman alum ; 

 Florence lake, prepared, in the same pro- 

 cess, from the sediment of cochineal, by 

 precipitation with solution of tin; and 

 madder lake, prepared from Dutch crop 

 madder, by precipitation with alum. 



LAKE (in Geography). An inland 

 body of water not connected with the 

 ocean or any of its branches. It is formed 

 by accumulation of water in a basin, or 

 depression of the surface, deeper than 

 the general slope of the water-line of 

 valleys. There are four distinct kinds of 

 lakes : — 



1. Thos6 which have no outlet, and 

 which do not receive any running water. 

 They are usually very small ; some ap- 

 pear to be the craters of extinct volcanoes 

 filled with water. 



2. Those which have an outlet, but 

 which receive no running water. They 

 have been formed by springs flowing 

 into some large hollow ; the outlets are, in 

 some cases, the beginnings of very large 

 rivers. These lakes are usually in ele- 

 vated situations. 



3. Those which both receive and dis- 

 charge streams of water, as the immense 

 bodies of water in North America, be- 

 tween Canada and the United States, the 



