421 



GLYCOLLAMIDE. 



GNOMIC POETS OF GREECE, 



422 



The further study of the glycols and their derivatives may be 

 expected to throw light on many bodies whose relations are at 

 present obscure or unknown. Probably meconin and saligeuin will 

 be found to be biatomic alcohols. Berthelot has obtained a com- 

 bination of stearic acid with meconin, which has the formula : 



glycolh'c acid as lactide does to lactic acid, and is formed by the action 

 of heat upon tartronic acid : 



C,H,0 10 = C a 4 + CJIjO. + 2HO 



(C SO H 8 0.)" I 



* 



And saligenin, C 14 H 4 , appears to be the glycol corresponding to 



f TT " 1 



salicylic acid, "rr > O t . ] 



GLYCOLIC ACID (C,H 4 ). This acid is the lowest member of 

 the series of acids to which lactic and leucic acids belong, and recent 

 researches have established a close relation between it and glycoL 



It is formed by a variety of processes. It was first obtained by the 

 action of nitrous acid on glycocoll. An aqueous solution of glycocoll 

 is saturated with nitrons acid, and the solution extracted with ether ; 

 on the evaporation of the ethereal solution, the acid is left in the form 

 of a thick syrup. The action is analogous to that by which aloiiin, 

 the honiologue of glycocoll, is converted into lactic acid : 



HO 



C.H.XO, 



Glycocoll. 



NO, 



= C 4 H,O, 



Nitrous 

 acid. 



Glycolic acid also occurs among the products of the oxidation of alcohol 

 by nitric acid. It is also formed by the oxidation of glycol. 



Another mode of its formation also shows its relation to lactic acid. 

 When tartraric acid (C,,H 8 O 10 ), an acid produced by the spontaneous 

 decomposition of nitrotartaric acid, id heated, it decomposes iato water, 

 carbonic acid, and tjlycMide : 



C H 8 JO = C,H S 4 + 4HO + 2CO, 



Tartraric acid. Giycollide. 



Glycollidc stands to glycolic acid in the same relation as lactide to 

 lactic acid : it is the anhydride of glycolic acid. When it is digested 

 for some time in the warm with water, it assimilates 2 eq. of water, 

 and becomes converted into glycolic acid. 



Perhaps the best method of preparing glycolic acid is by the spon 

 taneouB decomposition of chloracetic acid. When an aqueous solution 

 of ehloracetate of potash is heated in a closed vessel to between 250 

 and 280 Fahr., chloride of potassium is formed, and the solution 

 contains glycolic acid : 



Tartronic acid. 



Glycollide. 



C,^ S C1K0 4 + 2HO 



Chloracctate 

 of potash. 



C,H 4 0. + KC1 



Chloride 

 of potuuium. 



Glycolic acid, in its state of greatest concentration, has the form of a 

 thick syrup, which, dried in vacuo over sulphuric acid, forms long 

 well-defined crystals. It is miscible with water, alcohol, and ether, in 

 all proportions. Its aqueous solution decomposes carbonates. The 

 zinc salt has the formula C,H a ZnO, + 2 aq., and greatly resembles the 

 corresponding lactate of zinc. When glycolic acid is mixed with 

 acetate of lead, and excess -of ammonia added, a white precipitate is 

 formed. By this deportment it is distinguished from lactic acid, which, 

 under the same circumstances, remains clear. GlycdaU j 

 (C.HjCaO,) crystallises from a hot aqueous solution in stellate groups 

 of very fine asbestos-like needles. It is quite insoluble in alcohol, even 

 when dilute, and is hence easily separated from lactate of lime, which 

 is soluble. 



Glycolic acid stands in the same relation to glycol as acetic acid to 

 alcohol. Both acids are derived from their corresponding alcohols by 

 direct oxidation : 



C.H.O, + O. 



C.H.O, + 2HO 



Glycol. 



Acetic acid. 



Glycolic acid. 



2HO 



When the oxidation of glycol is more energetic, oxalic acid is formed. 

 These 1 two acids represent, in a certain sense, the degrees of oxidation of 

 glycol. Thus 



C.H.O," ) 

 H, } 



Glycol. 



Glycolic acid. 



Oxalic acid. 



It is a white tasteless powder, insoluble in cold water, and very slightly 

 so in hot. Treated with ammonia, it is transformed into ylycMumide : 

 C 4 H S 4 + KH, = C^HjNO. 



Glycollide. .Glycollamide. 



Glycollamide forms fine colourless crystals, very soluble in water, 

 sparingly soluble in alcohol, and possessing a slightly sweet taste. It 

 is isouieric with sugar of gelatin. 



GLYCOCHOLALIC ACID. [CHOLIC Acn>.] 



GLYCOCHOUC ACID. [CHOLIC ACID.] 



GLYCOSINE. [GLYOOL, Glycosine.] 



GLYCYL (CjHjOj). A hypothetical radical, supposed to be contained 



in GLYCERIN, whose formula then becomes V, 3 I O a + 5 f 2 . 



GLYCYRHIZA GLABRA, and G. ecldnaia, liquorice, of which the 

 root, or rather the rhizoma, and a watery extract are officinal. These 

 are natives of Germany and south of Europe, but cultivated exten- 

 sively in some parts of Britain ; the extract is however chiefly prepared 

 in Spain, Italy, and >Sicily, and imported under the name of Spanish 

 juice or liquorice : the finest is called Solazzi. The rhizoma is generally 

 allowed to attain the age of three years, and is then taken up. It is 

 often several feet in length, and about half an inch thick. The odour 

 is faint, the taste sweet but mawkish ; and if the bark be chewed, it is 

 at last rather acrid, which is owing to the presence of a soft resin, or 

 oleo-resin. 



Robiquet found it to contain a peculiar sugar, which is uncrystal- 

 lisable and uufermentable, -called ylycion, or ylycyrhi-in, and other 

 matters. 



Infused in warm, or macerated in cold water, it affords a mucilaginous 

 fluid, which is bland and demulcent. The powder is much used to 

 involve recently made pills, in order to prevent them from adhering to 

 each other. Before using it for an infusion, or to powder it, the bark 

 should be removed, by which the bitterness is avoided. 



The extract is formed into rolls from 6 to 8 inches long, which are 

 dried, and surrounded with bay leaves, to prevent them from adhering, 

 as in warm weather they have a tendency to melt, notwithstanding the 

 addition to them of starch or peas-meal : 100 Ibs. of the dried root 

 field 30 Ibs. of extract. 



Good liquorice juice is black, dry, easily broken (in cold weather), 

 with a shining fracture. It should dissolve easily and entirely in the 

 mouth when pure ; but crude liquorice, besides starch or meal, has 

 generally more or less copper, rarely brass, derived from the pans in 

 which it has been boiled ; it is therefore subjected to a process of 

 lurification, and is then termed refined liquorice. This is done by 

 melting it in water, draining off the solution, so as to leave the sand 

 and other impurities behind, and inspissating it ; then forming it into 

 more slender cylinders, which are generally soft and moist, even when 

 sugar has been added to them : a better addition is a small quantity of 

 ^in arabic. In Yorkshire an extract is prepared which is sold under 

 .he name of Pontefract cakts. 



Both the crude Spanish and refined liquorice are used as demulcents, 

 ,o allay tickling cough in slight cases of catarrh : often formed into 

 .ozenges, plain or medicated. The Trochiici ylycyrrhizte cum "/'''' 

 ivowedly contain opium, but too many of the nostrums sold as cough 

 .ozenges contain morphia, to a considerable extent, and are therefore 

 dangerous when too freely used. 



GLYCYRRHIZIN (C lt S a O v or C^H^O,,). An unfermentescible 

 saccharine matter contained in liquorice root. It is a brown trans- 

 lucent amorphous substance, only slightly soluble in cold water, <ind 

 possessing a nauseous, saccharine, but slightly bitter, taste. Its hot 

 solutions gelatinise on cooling. 

 GLYOXALINE. [GLYCOL, Glyoxaliae.] 

 GLVOXYLIC ACID. [GLYCOL, Gtyoxylic ami] 

 GLYPTOGRAPHY. [Ei.ix"riio-MMALi,uiu,r.] 

 GNOMIC POETS OF GREECE. Under this title arc included 

 those moral and philosophical poets whose remains consist chiefly of 

 short sententious precepts or reflections. Such are the Gnouuu of 

 Theognis, which, though numbered consecutively as a connected poem 

 to 1200 lines, form in fact a collection of unconnected members, varying 

 from two to thirty lines in length. Such also were the sentences 

 inscribed by Hipparchus on the Hernuu in the streets of Athens. 

 These metrical precepta were valuable before writing became common ; 

 being, like proverbs, serviceable and easily-remembered rules of conduct. 



In accordance with this view, glycolic acid must be bibasic. Hithert 

 only monobasic salts have been formed. Its homologue, however 

 lactic acid (which is a derivative of propylglycol, the homologue o 

 glycol), is bibasic, and it is to be expected that further research 

 establish the bibasicity of glycolic acid. [GLYCOL.l 



GLYCOLLAMIDK. [GLYCOLLIDE.] 



QLYCOLLIDE (C.H.O,). This body stands in the same relation tc 



1677, and later editions) contains a collection of the Gnomic ports. 

 They have also been edited by Brunck (' Gnomici 1'oetto Gucci,' 

 Argent., 1784, 4to.). The principal authors contained in this edition 

 are Theognis, Tyrtajus, Solon, Simonides, with many others, some to 

 the extent only of a fow lines. Tyrtscua and Simonkles, however, 

 though the authors of Guomw, hardly come under the definition abovo 



