260 Mr Purvis, The conversion of saw-dust into sugar 



(7) 50 grams of saw-dust were digested with 500 c.c. water 

 and 100 c.c. N/1 H2SO4 (= 2-45 grms. H.SO4) for 2 hours. This 

 produced 1'82 °/^ dextrose. 



(8) 25 grams of saw-dust were digested with 700 c.c. water 

 and 5 grams P0O5 for 12 hours at the temperature of the room 

 (about 15° C), and then for 3 hours just below the boiling point. 

 This gave 12'66 °/^ dextrose. 



The results show that the amount of sugar which can be 

 obtained depends on the nature of the acid and its strength relative 

 to the amount of saw-dust, and on the time of digestion. The 

 greatest amount was obtained when the strongest sulphuric acid 

 acted for a considerable time. In the other experiments not so 

 much was obtained as by the Classen process. For the commercial 

 production of sugar from such a cheap material as saw-dust the 

 question to be decided would be the relative cost of the Classen 

 process compared with the cost under the conditions of these 

 experiments. That would include a comparison of the cost of 

 the various acids and the recovery of these acids for further use. 

 The conversion of sugar into alcohol and acetone presents no 

 difficulty ; and it would be important to consider whether such 

 useful chemical substances could not be produced from a waste 

 product like saw-dust at a cheaper rate than by the present costly 

 methods. 



