LAO 



LAC 



fresh lac, incrusting twigs of trees, 

 is called slick lac; the resin being 

 separated, pounded, and stirred witli 

 water, yields a red solution, which, 

 when evaporated to dryness, forms 

 lac dye, the insoluble portion being 

 grain lac, and, when melted and run 

 on leaves or wood, shell lac. 



LAC DYE. This is found in small 

 cakes ; it is dissolved in a mixture of 

 3 lbs. tin and 60 muriatic acid. To 

 produce a rich scarlet, the cloth is 

 mordanted with solution of tin. 



LAC, SHELL. This is much used 

 for the best sealing-wax by various 

 manufacturers, and in varnishes. It 

 is rapidly dissolved by strong alco- 

 hol, by dilute muriatic and acetic 

 acids. Laccine and laccic acids are 

 bodies found in lac. 



LACERATED. A botanical term, 

 used to designate a leaf which ap- 

 pears to have been torn. 



LACERTID-E. The family of liz- 

 ards. 



LACHRYMAL GLAND. A small 

 conglomerate gland placed in the up- 

 per portion of the outer angle of the 

 eye ; it supplies the eye with moist- 

 ure to lubricate the surface ; an ex- 

 cessive flow produces tears. The 

 lachrymal duct is a small channel 

 from the inner corner of the eye to 

 the inside of the nose. 



LACINL\TE. Fringe-like ; petals, 

 leaves, &c., cut into numerous thin 

 shreds. 



LACQUER. A varnish used to 

 cover brass and other metals, made 

 by dissolving shell lac in alcohol, and 

 colouring with gamboge, saffron, and 

 other bodies. 



LACTARY. A dairy. 



LACTATION. Giving milk, or 

 Buckling. 



LACTEALS. Minute vessels run- 

 ning from the interior of the small 

 intestines along the mesentery to the 

 thoracic duct ; they convey the chyle 

 or nutritious portions of digested 

 food. They form the lacteal glands 

 of the mesentery. 



LA CTIC ACID. The acid of sour 



milk ; it is also found in digested food, 



and sour starchy substances, saur 



kraut, &c. It is a thick, colourless, 



44S 



sour liquid, soluble in water and al- 

 cohol, and coagulates milk : formula 

 C„ H4 O4. It readily combines with 

 bases, forming lactates. 



LACTINE. Sugar of milk. 



LACTOMETER, or GALACTOM- 

 ETER. " A term applied to a glass 

 tube for ascertaining the proportion 

 which the cream bears to the milk of 

 any particular cow, or the produce 

 of a whole dairy. Lactometers of 

 different kinds have been invented ; 

 the best is called the four or five glass 

 lactometer {Fig.). 



/— t^-i^-l^-l^ 



"The principle of the instrument 

 is, that if new milk is poured into 

 glass tubes and allowed to remain, 

 the division between the cream which 

 floats upon the surface of the milk 

 will be so evident that its depth may 

 be easily measured ; and should the 

 milk from any cow produce jiiore 

 cream than that of another, the dif- 

 fei-ence will be seen by the divisions 

 or marks on the glass tubes. The lac- 

 tometer consists of four or five glass 

 tubes, about half an inch diameter 

 and 11 inches long, fitted into an up- 

 right mahogany frame ; each tube 

 having a fine line drawn round it 10 

 inches from the bottom ; three inch- 

 es from the line downward it is grad- 

 uated into inches and tenths of inch- 

 es. At milking time each tube is to 

 be filled up to the line with new milk. 

 After standing 12 hours, the quantity 

 of cream which floats upon the sur- 

 face is shown by the scale of inches 

 and tenths ; each division will there- 

 fore represent one per cent, of the 

 whole. 



" If the milk given by a cow at one 

 meal is one gallon, or eight pints, and 

 the thickness or depth of the cream 

 which floats upon it measures 14 di 

 visions, multiply the number of pints, 

 8, by the depth of the cream, 14 ; the 



