LAUMONTITE 45 



In either case the iron plate should be made as hot as the fluid metal, -which, by 

 entering the holes, becomes firmly united to the iron, especially if the holes are largest 

 on the reverse side, or that away from the lead. Holtzapffel. 



Lap is also a roll or sliver of cotton for feeding the cards of a spinning machine. 



LARD. The fat of the pig. 



X.AB.D OXXi. Lard being subjected to a pressure, an oil, oleine, is expressed, stearine 

 being left. This lard oil is much used for lubricating machinery, and it has been em- 

 ployed for the adulteration of olive oil. 



LARDEREIiIiITE. A borate of ammonia, from the boracic-acid lagoons of 

 Tuscany. 



IiASKS. All Indian cut stones are called lasks. They are in general ill-shaped 

 or irregular in their form, their depth ill-proportioned, and the table, or face, seldom in 

 the centre of the stone, sometimes too broad or too small, and none properly polished. 

 The chief thing regarded is saving the size and weight of the stone. These stones are 

 always new wrought when brought to Europe. 



IiATHE-CORDS. Cords for turning lathes. These cords are made of intestines 

 of horses, cleaned and prepared by the separation of the mucous membrane in the 

 manner described under GOLD BEATEES' SKIN". A wooden ball, armed in its lower 

 part with four cutting blades, at equal distances from each other, is fixed by an 

 upright piece of wood to a bench. The end of an intestine is then drawn over this ball, 

 and as the gut is pulled downwards it is divided into four equal bands or strips. 



Four or eight of these strips, according to the thickness which it is intended to give 

 to the cord, are tied with a peculiar knot to one end of a thick piece of cord. The end 

 is passed around a peg introduced into a hole in a solid post, to the side of which a 

 number of pegs are attached. At a distance of ten or eleven yards from the first 

 one, another post is fixed, similarly provided with pegs, and over one of these latter 

 the middle of the assemblage of strips is passed, the other end being brought back, and 

 attached to the first peg by means of another knotted cord. The tied end of the strisp 

 is then attached to the wheel by a hook connected with the whirl, which is made to 

 revolve until the strips are sufficiently twisted. The twisted end is then kept 

 stretched by attaching it to the peg, and any projecting filaments are cut off. After 

 being stretched for some time, the cords are then twisted again, and a third and 

 a fourth time are twisted by hand, being each time rubbed with and drawn through a 

 bunch of moistened horsehair after the twisting, and again stretched out between the 

 two posts. If the cord is not smooth and even after the twisting is completed, it is 

 made so by rubbing with a piece of dog-skin. It is then dried, and by some makers 

 is exposed to the vapours of sulphur. At last the ends are cut off, and the cord is 

 rolled in a coil. 



In order to avoid the putrid emanations, from the intestines, which are generally 

 in an incipient state of decomposition, Labarraqua recommends to clean them at 

 once, turn the inside out, and put them to soak over night in a cask containing, for 

 fifteen or twenty intestines, chloride of potash, at 13 or 18, 1 Ib. ; water, 4 gallons. 

 The mucous membrane is ready to be detached the next day ; and after its removal, 

 and a thorough washing, the intestines can at once be prepared, as has been already 

 described. 



LATH WOOD. The outside cuttings of fir-trees, used for being split into laths. 



IiATTJGN is a somewhat antiquated term, which was applied to several kinds of 

 sheet metal. ' Mines of latten, whatever may have been meant by the word, are men- 

 tioned in the time of Henry VI., who made his chaplain, John Botteright, comp- 

 troller of all his mines of gold, silver, copper, latten, lead, within the counties of 

 Devon and Cornwall.' Is tin meant by the term ? Watson's Chemical Essays. 



In the reigns of Henry VIII. and Edward VI., several acts of parliament were 

 passed, prohibiting the exportation of brass, copper, latten, bell-metal, gun-metal, 

 schrof metal, &c. "Windows framed with lead are called lattice windows in the 

 West of England. 



The term is now applied to sheet or plate brass. Black latten is rolled sheets ; 

 shaven latten is in thinner sheets ; and roll latten is polished on both sides. 



LAUGHING GAS. The popular name of nitrous oxide or nitrogen monoxide, 

 NO (K 2 O). It is best prepared by heating solid nitrate of ammonia, this salt being 

 resolved by heat into laughing gas and water. The gas, when inhaled, produces a 

 pecxuiar intoxicating effect, usually without being followed by any ill consequences. 

 Of late years laughing gas has been largely used by dentists as an anaesthetic. Care, 

 however, is needed in administering it, as it may produce serious results on individuals 

 suffering from certain affections of the heart. 



LAUIVZOWTITE, or Efflorescing -zeolite. A hydrous silicate of alumina and lime, 

 occurring in cavities in amygdaloidal trap rocks and in- metalliferous veins. It is 

 common in some of the copper deposks of Lake ^Superior. 



