73 



LACERTA. 



LACTIC ACID. 



74 



kind of machine-made silk-net; while machines on Heathcoat's 

 principle have borne down all opposition at Nottingham and elsewhere. 

 They did not, however, drive out the warp machines, which are 

 found to be suitable for a particular class of goods, blond, edging, net, 

 and lace of silk : tattings, pearl trimmings, net, and lace, of cotton ; 

 D'Oyleys, anti-macassars, and other articles of a cheap and durable 

 kind. Mr. Felkin, in 1843, estimated that there were at that time 300 

 of these machines at work upon silk, 500 upon cotton, 5000 hands 

 employed, and 350,OOOZ. worth of goods annually produced, of which 

 290,OOOJ. was available as wages, interest, and profit. 



In a later estimate, in relation to the whole trade, Mr. Felkin stated 

 that in 1856 there were 3500 machines making net, many as much as 

 five yards in width, and all averaging three yards. More than half 

 were engaged on fancy net or lace ; and of the other half 1300 were 

 rotary circular machines, making plain goods. Many fine large 

 factories had been built at Nottingham since 1850, to work these 

 machines. The returns he set down at about 3,000,000 annually, of 

 which 2,200,000/. was divided among the masters and workmen for 

 interest, profit, and wages, leaving the rest for the purchase of raw 

 material. There were 115 wholesale firms in Nottingham alone, 

 engaged in this trade. The ootton-yarn used for net varies from No. 20 

 to No. 400, the latter of which is so fine that 100 miles of it would 

 barely weigh a pound. We may remark that quitting, tattiny, saidpearl- 

 lace or net are all made in narrow strips. 



In the processes of ' lace-running' and 'tambouring,' largely earned on 

 in and near Nottingham, the operation approaches more nearly to a 

 kind of weaving; for the bobbin-net, which forms the ground, is 

 stretched horizontally on a frame, and the lace-runner works a series 

 of ornamenta in the net by a needle threaded with coarse cotton, the 

 pattern being previously marked on the net. In the process of ' tam- 

 bouring' net, the cotton thread is carried to and fro between the 

 meshes of the net by means of a very fine and small hook, which gives 

 to the decorative figure thus produced much more the appearance of 

 chain-work than the instance above noticed. /'/</.<. .3 and 6 show the 



Fig. 0. Kun Lace. 



difference between machine-lace and run-lace that in which the 

 device is worked by the machine, and that wherein the device is 

 wrought by a needle on plain net. 



Lace-making and net making machines have been introduced into 

 France and Belgium, mostly from England ; but Nottingham still 

 continues to be the head-quarters of the trade. 



LACERTA (the Lizard), a constellation of Hevelius, surrounded by 



Andromeda, Cepheus, Cygnue, and Pegasus. The following are the 



; il stars in this constellation. 



No. in Catalogue 

 No. in Catalogue of British 



Character. of Flanuilced. Association. Magnitude. 

 a 1 7855 4 



P 3 7815 4 



LACHRYMAL ORGANS, DISEASES OF THE. The lachrymal 

 gland is very rarely the seat of disease. It sometimes suppurates 

 from acute inflammation, but it is more commonly affected with a 

 chrome enlargement and induration, forming a prominent tumour 

 under the upper eyelid, which pushes the eye downwards and inwards. 



In this state it may be removed without difficulty and with perfect 

 safety from beneath the eyelid. 



The most frequent disease of these organs is that commonly called 

 fistula lachrymalis, which consists of inflammation of the lachrymal 

 sac. [EYE, NAT. HIST. Div.] When the inflammation is acute, it 

 forms a tumour of about the size and shape of a horsa-bean at the 

 inner side of the eye, which is firm, red, hot, and extremely painful. 

 The nasal duct being closed, the tears, which should pass through 

 it into the nose, flow continually over the cheek, and produce redness 

 and excoriation. The eyelids swell, and the pain and tension are 

 sometimes so severe as to excite considerable fever and even delirium. 

 If the inflammation be not early checked, suppuration takes place, 

 and the matter may escape by an opening, which sometimes remains 

 for a long time fistulous, at the corner of the eye. The treatment 

 must be actively reducing, and when suppuration has taken place 

 an early opening should be made into the sac at its most prominent 

 part. 



In the chronic inflammation of the lachrymal sac, which often 

 succeeds to the acute, the nasal duct continuing obstructed, the sac 

 becomes frequently distended with its secretion, and a mixture of 

 mucous and purulent matter may be pressed out of it through the 

 puncta lachrymalia. In some cases no other inconvenience is pro- 

 duced than that of the necessity of pressing out the contents of the 

 sac once or twice a day ; but in others, attacks of acute inflammation 

 are apt to supervene, and excite very painful affections both of the 

 lachrymal apparatus and the eye itself. In the first instance, leeches 

 and other antiphlogistic remedies should be employed ; but if they 

 are unsuccessful, astringent lotions should be applied to the eye, that 

 they may be imbibed by the puncta lachrymalia, and conveyed through 

 them to the nasal duct. But if these means fail, the lachrymal sac 

 must be punctured near the inner angle of the eye, and a probe passed 

 through it into the nose. A portion of bougie must be introduced 

 into the passage thus restored ; the canal will enlarge around it so as 

 to permit the tears to pass through, and after a few days the bougie 

 may be exchanged for a nail-headed style, which must be worn in the 

 canal and sac for a considerable time. 



LACHRYMATORY, a small earthen or glass vessel, generally with 

 a long neck, found in the sepulchres of the ancients. Chifflet, in his 

 ' Lachryimc prisco ritu diffusoe,' first started the idea that they were 

 intended to hold the tears of relatives or friends, who assisted at the 

 funeral rites ; and the notion was long supported by the antiquaries 

 of different countries throughout Europe. It was afterwards com- 

 bated by Schccpflin and Paciaudi, and as no such use of these phials or 

 little bottles can be discovered in passages of the Roman writers, the 

 conclusion was at length come to that they were intended to contain 

 perfumes or balms only for sprinkling upon the funeral pile. 



LACQUERING. [JAFANSINS ; VAIINISH.] 



LACTAMIC ACID. [LACTIC ACID.] 



LACTAMIDE. [LACTIC ACID.] 



LACTIC ACID (from lacte, milk) (G'^H^O,,,) is the substance that 

 gives the weh 1 known acidity to sour milk. It is produced from the 

 milk-sugar by the fermentive action of the casein or cheese portion. 

 This acid is also met with in many other processes where starches or 

 sugars other than milk-sugar are undergoing fermentation. It occurs 

 in the fluids of the muscular tissue. When required in quantity lactic 

 acid is most conveniently prepared by adding one part of common 

 cheese to a solution of eight parts of milk-sugar in about fifty of water, 

 stirring in three parts of powdered chalk and setting the whole aside 

 for two or three weeks, in a warm place (80 Fahr.). The mixture 

 slowly becomes filled with crystals of lactatc of lime, these are 

 separated by straining, purified by re-crystallisation from water, 

 decomposed with about one-third of their weight of sulphuric acid, 

 and the liquor, freed from the sulphate of lime by filtration, is 

 decolorised by treatment with animal charcoal, and concentrated by 

 evaporation. 



Lactic acid is uncrystallisable. When pure it has the consistence of 

 strong syrup, is transparent, colourless, inodorous, of intensely acid 

 taste, and has a specific gravity of 1'21. Exposed to the air it absorbs 

 water, in which it is soluble in all proportions. It is also very soluble 

 in alcohol and ether. An exceedingly minute quantity of it at onco 

 causes the coagulation of boiling milk. Nitric acid converts it into 

 oxalic acid. By careful application of heat to lactic acid, contained in 

 vessels from which air is excluded, it may be distilled ; but at a tem- 

 perature of 600 Fahr. ia converted into carbonic acid, aldehyd, 

 citraconic acid, lactide (C 12 H 8 0,), and lactone (C 10 H e O,). By the 

 continued action of a heat of about 266 Fahr. lactic acid is gradually 

 converted into lactic anhydride (C,.iH 1() ]n ), a fusible, bitter substance 

 of yellow colour, insoluble in water, but gradually re-converted by 

 prolonged contact with that liquid into lactic acid. 



Lactone (CmHjO,) is a pungent volatile liquid. Boiling point 

 1<J8 Fahr. 



Lactide (C^K^O,), obtained in the manner just described, crystal- 

 lises from alcohol in clear white rliomboidal tables. It may be 

 sublimed without undergoing decomposition. Water gradually con- 

 verts it into lactic acid, and ammonia forms with it lactamide. 



Laclidi-. 



2NH 3 



Ammonia. 



LucUimide, 



