54 BUULETIISr 983, U. S. DEPARTMENT, OF AGRICULTURE. 



Theoretically, hydrochloric acid, because of its maximum ionization 

 should produce even greater sugar yields than sulphuric acid. Hydro- 

 chloric acid presents greater technical difficulties than does sulphuric 

 acid, and its cost is greater; however, if the yield were increased 

 sufficiently, the other difficulties could probably be overcome. Two 

 concentrations of hydrochloric acid were therefore tried, one of 1.80 

 per cent and another of 2.50 per cent, based on dry- wood weight, 

 and the respective total sugar yields were 19.69 per cent and 17.02 

 per cent. The complete data on cooks Nos. 89 and 90 are given in 

 the tables in the Appendix. That yeast is intolerant of the CI ion 

 is well known, and the laboratory workers were unable, as others 

 before had been, to obtain any fermentations. Unless, therefore, 

 the CI ion is removed by precipitation, as with silver nitrate, fer- 

 mentation is impossible. No fermentation was obtained when 

 chlorine or chlorides were used. The chief interest of the following 

 experiments, therefore, is in the data adduced with respect to total 

 sugars, for, as stated before, if it were possible materially to increase 

 the total sugars obtained, other difficulties might possibly be over- 

 come. 



Spruce. 

 7.5 atmospheres; 125 per centof n 2 0. 



►1.8 per cent of hydrochloric acid j ! q' rq 



2.5 per cent of hydrochloric acid , 17. 02 



1.3 per cent of sulphuric acid plus salt (NaCl) for equation H2S0 4 +Na01= 



NaHS0 4 +HCl 



1.8 per cent of sulphuric acid plus salt (NaCl) for equation H2S0 4 +2NaCl=Na 2 S0 4 + 



2 HOI 



2 per cent of chlorine from 2 KCIO3+H2SO4+IO HC1= K 2 S0 4 -1-6 H 2 0-H> Cl 2 



1.8 per centof sulphuric acid plus 10 per cent of KC10 3 tomake2 KC10 3 +H2S0 4 = 



K2SOH-2 HCIO3 



1.8 per cent of sulphuric acid plus 50 per cent of KCIO3 to make 2 KCIO3+ 



H 2 S0 4 =K 2 S0 4 +2 HCIO3 21.45 



20.44 



19.44 

 19.59 



The above table shows no yields of total sugars greater than it is 

 possible to obtain with the use of sulphuric acid only. Even if all 

 the sugars produced were fermentable and could be fermented, the 

 yield would not justify the added expense. Simple chloride and 

 chlorine treatments in their technical aspect may, therefore, be 

 dismissed, although the results are of interest in their bearing on 

 the chemistry of wood. 



The next experiment was with the use of ferrous sulphate in con- 

 junction with sulphuric acid — that is, with an increase in the con- 

 centration of sulphate ions. The result, especially when taken in 

 connection with the experiments on niter cake described below, is of 



