324 Cellulose 



It is to be noted that there was no preliminary treatment of 

 the wood by alkaline hydrolysis. These authors also establish 

 the quantitative constancy of the reaction in successive treat- 

 ments of the lignocellulose with chlorine, followed by removal 

 of the chlorinated product, until the cellulose stage is ap- 

 proached; only then is there any evident oxidation of the 

 cellulose. 



The chlorination reaction affords, therefore, a simple dissec- 

 tion of any lignocellulose ; the chlorinated lignone is constant 

 in composition for any given lignocellulose. In the case 

 of pine-wood it is approximately C 24 H 28 C1,O 10 . 



The reaction is therefore of first importance in determining 

 the constitution of the most characteristic component of the 

 lignone complex, and it is the basis of the now standard method 

 of isolating cellulose for estimation. We may mention a further 

 application, in diagnosing the state of purity of industrial wood 

 celluloses : in this case the hydrochloric acid formed is a measure 

 of residual lignone. 



The reaction of phloroglucinol with the lignocellulose as a 

 gravimetric method of estimation has recognised advantages 

 over the colorimetric method, and is generally adopted. As we 

 have pointed out (Berl. Ber. 40, 5119), the total reaction of 

 combination with the phenol is characteristic of a group which 

 is easily brought into the non-reactive state as regards colour 

 development, without affecting the main reaction. Never- 

 theless, the colour reaction is remarkably constant for the 

 lignocelluloses in their * natural ' state, and proportional to the 

 degree of lignification. 



We have determined the maximum for this reaction, under 

 special conditions of experiment, and found for pine-wood : 



Phloroglucinol combining 6'o p.ct. of the lignocellulose 



Pyrogallol 7-6 



each phenol as C 6 H 6 O 3 . (J. Soc. Dyers, 1906.) 



