OLTCOL. 



GLYCOL. 



By the action at bydriodio acid on glycol, iodide of ethylene U 

 formed: 



< !. 



r. 



add. 



Iodide of 



ft h \Irll*. 



By modifying the action of hydrfodlc acM, an iodhydrln of glycol 



/ ( '.. ) \ 



( H 0, V corresponding to the chlorhydrin, appears to be formed. 



There is also an iodaoetin of glycol analogous both in preparation and 

 propertiea to the chloracotin of glycol. 



'.nytyf.Jir ariil. Sulphuric acid by it action on glycol forms a 



mil analogous to sulphovinic acid, which has however hitherto 



only been examined in the Kiryta salt. Equivalent quantities of 



jnl Milplmric acid are mixed together, heated for some time, 



i!i!'.:t< '!. neutralised with carbonate of baryta, and evaporated. 



Sidpli'^l.V'-olaU- of baryta is a somewhat deliquescent salt. Sulphuric 

 acid precipitates sulphate of baryta from its aqueous solution, but 

 baryta water produce* no precipitate at least not in the oofd. The 

 formation of sulphoglyeolic acid may be thus expressed. 



'JO. + MO.H = 



c.n.o, 



8,0, 



-f 2HO 



Olvcol. 



Stllphoglycolio 

 acid. 



When the acid is neutralised by carbonate of baryta, hydrogen in 



','f s o,; 



replaced by barium, and we hare the salt, S,O 4 > 0,. Sulphoglyeolic 



acid is monobasic. 



ill axd fll<^ri/tie acid. These are two bodies, the former an 

 aldehyde, and the latter an acid, discovered by Debus, among the pro- 



f the oxidation of alcohol by nitric acid. As they belong to 

 the iflycol aeries a brief description of them is here necessary, while for 

 fuller details the reader is referred to Debus' original papers (' I'liil. 

 Mag.,' vol. xii. p. 361). 



nl (U.H.,0,), when pure, fa a solid, amorphous, pale-yellowish 

 mass, which deliquesces in the air, and is very soluble in alcohol and 

 ether. It has all the properties of an aldehyde, it reduces silver salts, 

 and forms crystalline compounds with alkaline bisulphites, from which 

 glyoxnl is obtained by treatment with dilute acids. The action of 

 ammonia on glyoxal yields two well-defined crystallised bodies, gtyeo- 

 me and gly<uraHnt. 



Glin-ofint (C.JIjX.) forms a light white, inodorous, and tasteless 

 white powder, which can be sublimed without change. Its hydro- 

 chlorate forms crystals, frequently an inch long. Its platinum 

 tin.- formula, f, h -TtCl,. The formation of glycosine from 



glyoxal and ammonia is analogous to that of amarine from oil of bitter 

 almonds and. ammonia, and may be expressed by the equation : 



3T.II/I.) + 4NTT, 



12HO 



Glyoxal. Glyconine. 



t (CjH.KT,) crystallises with difficulty; its acid oxalate 

 forms colourless prisms, and its platinum salt, C H,N,, HC1, PtCl 

 crystallises in splendid orange-red prii-v 



Ite formation may be represented by the equation : 



(C.H,0,) + 2XH, = C.n.N, + C,H,0, + 4HO 



Glynxnl. 



Glyoxallnp. Formic acid. 



< \TI.O,, appears on the evaporation of its aqueous 



in the form of a tough, transparent, pale-yellowish 



syrup, wliii-h neither crystallises nor solidifies. Its aqueous solution 



decomposes carbonates, and saturates strong bases. It is volatile with- 



iiut deeomp * . oxylic acid is a monobasic acid. Ite salts have 



neml formula. C.H^MO,. They mostly erystallise well. 



the aldehyde of glycol; it is intermedi i glycol 



Mid oxalic acid, and occurs among the products of the dim t xid-itjoi 

 of tflyrol. Its analogy to common aldehyde is well seen in the modo 

 of its formation \ 



<r.O, -f- 30 = C.H.O, + HO 



Alcohol. Aldehyde. 



C.H.O. -f 40 ',H,0, + 4110 



Oljrcol. 



i, I 



(ilyoxyllc acid is an intcrniediate compound Ixjtween glycolic anc 

 oxalic acids, jutt as oil of bitter almonds is intermediate between 



.; acid : 

 i-.ll.o. r 1( n.O, 



: add. 



Bi nij lie alcohol. 



O.H.O. 



Glyoiyll* uU. 



c,n,o. 



OxaltouU. 



c,,n,o, 



OU of Miter almonOi. 

 r^H.0^ 



BsnsoteMid. 



Qlyoxylic acid when decomposed by alkalies, splits up into a glycolato 

 and on oxalate ; it also readily absorbs oxygen, and passes into oxalic 

 These decompositions are the exact analogues of those which 

 oil of bitter almonds experiences under the same conditions. 



These properties and re-actions of glycol prove its complete resem- 

 blanoe to alcohol ; and it may be expected that to every monobasic 

 alcohol, a biatomio alcohol or glycol will be found to correspond. 

 Besides glycol, three have been already discovered, pmpylic glyeo!, 

 butylic glycol, and amylio glycol, corresponding respectively to a mono- 

 atomic alcohol : 



C.H.O, C.H.O. 



Amyllc alcohol. 



Bntylio glycol. 

 C,.H,.0, 



Amyllc glyco'.. 



They are derived respectively from propylene, C^H,; butylrne, 

 C 5 H, ; and amylene, C,,,H, ; the hojnolognes of olefiant gas. These 

 atter substances, which are true biatomic radicals, by treatment with 

 jromine form biatomic bi-omides, CaH/Br,, C,H,"Br,,, and ' 

 and these bromides, by acting on 2 eq. acetate of silver, yield the acetate 

 of the corresponding glycol, from which, by treatment with potash, the 



yvol is obtained. 



The homologous series of alcohols exhibit a certain regularity in 

 their boiling points. For every increase of C,H 2 there is an increase 

 of 34 Fahr. in the boiling point. The glycols exhibit a similar but 

 inverse relation. The boiling points have hitherto been determined, 

 in most cases in too small quantities of substance to be considered aa 

 quite accurate, nevertheless a certain regularity has been observed. 

 The higher a glycol stands in the series, the lower are iU boiling point 

 and density. Thus : 



Glrcol 



Propylic glycol 

 Butylic glycol 

 Amylio glycol 



C.H.O. 

 C.H.O. 

 C.11,.0. 



1-125 

 1-051 



1-048 



i. -- 



Boiling Point. 

 387 Fahr. 

 372 1 

 SGI" 

 SiO 1 



To each member of the series of homologous monoatomic alcohols, 

 there is a corresponding acid, a member <>f the fatty acid *erir 

 similarly there is a homologous series of aoids parallel with the glycolc, 

 and which are derived from them by direct oxidation : 



C.H.O. + 40 = C,H,0. + 



2IIO 



Glycol. Glycolic acid. 



C.H.O, + 40 = C.H.O, + 200 



Propylio glycol. Lactic acid. 



C.11,,0, + 40 = C.H.O. + 2HO 



Butylic glycol. 



Dutylactlc acid. 



The acid corresponding to amylic glycol has not been disc' 

 On the other hand, teu3e add (C^rf-OJ, which has long b. 

 cognised as a homologue of lactic acid, probably corresponds to a 

 glycol hitlierto undiscovered, caprylic glycol, C N H lt OL 



The acetate of methylio glycol has been prepared from iodide of 



methylene, C,H,"I,. It has the formula (j^oji } - U ^ not 

 been possible to obtain from it mcthylic glyeol, as by treatment with 

 bases H is completely decomposed. 



A series of bodies has been obtained by Wicke, which are considered 

 to be derivatives of a glycol of the bemoio acid series. By the 



Tobemola (0,,H.'Cl t ) on acetate of silver, a substance u 



obtained whiehhastheformnU''o. This would be the 



^. 



formuhi of the acetate of a glycol, C,.H,b. ( corresponding to bei 

 alc.liol (C..H.O,). But Wicko has not been abl 

 glycol itself, from the tcndeney the oaUfOOBt has of producing 

 benzole aldehyde when decomposed by bases. The body exhi 

 several instances reactions, deviating from those of the ordinary 

 glycols, and until the subject has been further examined, it cannot be 

 red as the derivative of a true glycol. A similar compound 

 hat been obtained from the outdol scries. 



