GL.UKHOV 



3567 



GLYCERIN 



unnecessary fat. The cleansed bones 

 are afterwards placed in a vertical 

 boiler and steam -treated for the 

 extraction of the glue, and then 

 purified in shallow vats by heating 

 with alum, oxalic acid, or blood. 



Hide glues vary considerably in 

 strength with the part of the ani- 

 mal from which the skin comes. 

 Clippings and waste, useless for 

 leather-making, make excellent 

 glue. The skins are steeped in milk 

 of lime in wooden vats or cement 

 pits for two or three weeks, then 

 washed thoroughly and dried, the 

 glue afterwards being extracted by 

 slow boiling in open or closed ves- 

 sels. Scotch glues are manufac- 

 tured by placing the hides in a 

 loosely woven sack lowered into a 

 cauldron of water which is gradu- 

 ally brought to the boil. 



Glukhov. Town of Ukrainia, in 

 the govt. of Tchernigov. It is on the 

 Moscow -Kiev- Voronezh rly., 175m. 

 E. of Tchernigov. There are 

 rope and brick works, brew- 

 eries, and distilleries. Gluk- 

 hov was once the residence 

 of the hetman of the Little 

 Russian Cossacks. Pop. 15,000. 



Gluteal Muscles. Three mus- 

 cles, the G. inaximus, medius, and 

 minimus, which form the fleshy 

 mass of the buttock (Gr. gloutos, 

 rump). Their principal action is to 

 extend the thigh or straighten the 

 body after stooping. They also 

 assist to move the thigh outwards 

 and rotate the leg outwards. 



Gluten. Tough, elastic sub- 

 stance obtained from wheat flour 

 by washing it with water. The 

 flour is enclosed in a muslin bag 

 and kneaded under water. The 

 starch is washed away, and the 

 gluten, about 10 to 12 p.c. of the 

 flour, remains. Bread and biscuits 

 made from gluten are used as food 

 by patients suffering from diabetes 

 who are required to avoid the use 

 of starchy food. Gluten is a com- 

 pound of two substances, one 

 soluble and the other insoluble in 

 alcohol. The soluble portion can 

 again be separated into mucedin 

 and gliadin. 



Glutton OR WOLVERINE (Gulo 

 luscus). Carnivorous mammal of 

 the weasel group, found in the 



Glutton or wolverine, a species of weasel 



W. S. Berridge, F.Z.S. 



COtlS 



Glue. A, plant for extracting and 

 clarifying glue ; B, plant ior de- 

 greasing bones 



northern districts of Europe, Asia, 

 and N. America. It does not now 

 occur in Great Britain, 

 but its fossil remains are 

 not uncommon. It is 

 nearly 3 ft. in length, has 

 dark brown fur, and a 

 short, bushy tail. Of 

 heavy build, it walks with 

 something of the action 

 of a bear, is found in 

 forests, is nocturnal in 

 habit, and devours any 

 animal it can catch. It 

 is particularly expert in 

 digging rabbits out of 

 their burrows. 



Gly cas , MICHAEL ( 1 2th 

 century A.D.). Byzantine 

 historian. Probably a 

 native of Sicily or Cor- 

 cyra, he was the author 

 of a general history of the 

 world from the earliest 

 times down to 1118, the 

 end of the reign of 

 Alexius I Comnenus. The 

 work is written in a sim- 

 plerstyle than most of the 

 Byzantine histories. 



Glycerin OR GLYCEROI. 

 [C 3 H 6 (H0) 3 ] ; Thick 

 colourless liquid with a 

 sweet syrupy taste, ob- 

 tained by the decomposi- 

 tion of fats and oils in 

 the process of making 

 soap and candles. It was 

 discovered by Scheele in 

 1779 as a by-product in 

 the manufacture of lead 



plaster. Chevreul and Bracon- 

 net in 1817 showed that gly- 

 cerin is a component to the 

 extent of 9 to 11 p.c. of all fats 

 and oils. The discovery of nitro- 

 glycerin by Nobel in 1863 in- 

 creased the demand for glycerin 

 and caused it to be manufac- 

 tured on a large scale. 



Glycerin is produced to a 

 small extent in the fermentation 

 of sugar, but the chief sources 

 are the waste products of the 

 soap and candle maker. 

 When fats and oils are 

 : saponified with a caustic 

 alkali, the fatty acids 

 combine with the soda 

 or potash, and glycerin is 

 formed as a by-product. 

 This "sweet-water," as 

 it is called, is after- 

 wards purified and con- 

 centrated. The candle- 

 maker only requires the harder 

 portion or stearin of fats, and to 

 obtain this heats the fats with lime 

 or magnesia, either in open vessels 

 or in an autoclave, glycerin being 

 again obtained as the by-product. 

 Other methods of obtaining gly- 

 cerin from fats are by the acid 

 saponification process, Twitchell's 

 process, and by the use of a ferment 

 obtained from castor oil seeds. 

 These by - products are subse- 

 quently purified either by distilling 

 the crude glycerin with superheated 

 steam at ordinary pressure or in a 

 vacuum apparatus. Colour is re- 

 moved by treating the glycerin 

 with animal charcoal and water by 

 evaporation. The operation de- 

 mands skill 



Much distilled glycerin is used in 

 the manufacture of high explosives 

 such as dynamite, blasting gelatin, 

 and cordite. It is required to pass 

 special tests before it can safely be 



Glue. Left, glue tester. Right, stand of 



Khedjahl flasks used to estimate the percentage 



of glue in organic substances 



