[ 465 ) 



easily liydrolisod, llio ])e('tose of the tl;i\ Jiol so easily. Hereb\' lirst 

 result pectine oi- metapectine, wliicli have an acid character and are 

 therefoi'c also called pectinic acid and metapectinic acid. Tiie pectine 

 gelatinises in ])resence of lime, throngh the enzyme peclase, moreovei- 

 thi'ongh alkalies and ammonia, likewise in presence of a lime salt. 



In absence of lime the componnds of alkalies with the pectine 

 are solnbJe in water, (lelatinisation proper is unknown with mehx- 

 pectinic acid. 



With continued hydrolysis, pectine and metapectine, hence, also 

 pectose, [)roduce galactose and pentose, and according to TotJ;Kns, 

 with certain pectine kinds, dextrose and arabiiiose too, which sugars 

 are easily fermented by (rranulohacter. 



By boiling with nitric acid pectose and pectine yield mucous acid. 



Pectose is insolul)le in cold and boiling Avater and in cnpri- 

 oxyde-ammonia. The })ectose of the flax-sialk is moreover not easily 

 affected by dilute acids and alkalies, and remains nnchanged after 

 a short heating in water-vapour at 120° V. 



Pectose can be softened by the successive influence first of an 

 acid then of an alkali. If the flax-stalk is first extracted with 

 dilnte hydrochloric acid, by which the ])ectose changes into pectine, 

 which however, as an insoluble lamella, still holds the ceils together, 

 washed ont to remove the lime, salts become solnble by the hydro- 

 chloric acid, then treated with ammonia or natriumcarbonate, a conside- 

 rable softening takes place. On this method, first suggested by Mangin ^), 

 reposes the so-called chemical rotting after the patent of Baler, which 

 has, however, prodnced nothing of practical nse, and only shows that 

 the ''inventor" did not kiiow the reqniremenis to which well-rotted 

 flax shonld answer. 



A better way of dissolving the pectose of the flax-stalks we fonnd 

 by placing them in a strong solntion of ammonium-oxalate, but only 

 after 3 weeks the rotting process AAas completely finished, so that 

 this means has not au)' practical value either. 



Whereas the preparation of pure pectose is troublesome in conse- 

 quence of its insolubility, it is easy to make pectine. 



Herefor^) one takes the rootstocks of Gentiana hiU'd of the 

 chemists, grounds them finely, first extracts with H^ () and places 



1) Although it may be read everywhere lliat pectose aflei' Mangin's method 

 goes "into solution", it is my exi)erience that this is exaggeration, and that, of the 

 decomposition of parts of pUtnts into free cells as in rotting, there is no question 

 in this case. 



") To compare Bourquklot and Hkpjssey, Journal de IMiarmacie et de Ghimie, 

 Sér. 6, T. 8 p. 145, 181)8. 



