182 A. J. Ewart: 



The production of sugar from solids. 



If dry (CHaO^a is mixed with crystalline Barium hydrate (F» 

 HgOo 8 HoO) and ground intimately in a mortar, a pasty mass is- 

 obtained, smelling of CHoO. If this is gently warmed at one point 

 a sudden and violent exothermic reaction spreads through the mass, 

 CHjO, water vapour and methyl alcohol are given off, and the 

 temperature rises to 100° C. oi^ 110°C. if a large mass is used, wdth 

 an excess of barium hydrate. The resulting brown, gummy residue 

 contains no formaldehyde, but reducing sugar appears. 



Similar reactions are given with strontium hydrate, but with 

 dry calcium hydrate the reaction is imperfect. '' Paraformalde- 

 hyde" and the solid polyhydrate may be used instead of metafor- 

 maldehyde. In the latter case the temperature does not rise beyond 

 100"C., owing to the large escape of steam. 



Metaformaldehyde and alkali. 



The solid was ground with dry barium hydrate in varying mole- 

 cular proportions, and the pasty mass weighed out to contain in 

 each case 0.45 gram (CH20)3, After warming, the residue was dis- 

 solved in warm water, the Barium formate and any excess of 

 Barium hydrate precipitated as sulphate, and the filtrate tested by 

 the Pavy method. Any (CH20)3 remaining is filtered off with the 

 Barium sulphate, and if any CHoO is present, the ammonia used 

 the Pavy method^ (^ny (CHiO)^ remaining filtered off with the 

 affect the tests for reducing sugar. Similarly the formic acid is" 

 converted into ammonium formate. As a matter of fact the 

 reaction is a very complete one, and with the proper proportion of 

 barium hydrate every trace of formaldehyde is removed. 



The following proportions were used : — 



A and B. 1 Barium hydrate (0.85 g-ram) to 1.8 (CH.iO)3 (0.45 g-ramy 

 C 1 „ „ (0.42 „ ) to 3.6 (CH^O)., (0.45 gram) 



D and E. 1 „ „ (0.28 „ ) to 5.4 (CH.,0)3 (0.45 gram> 



with the following results — 



Proportion 



Final reaction 



Loss of weijfht 

 after warmiiiy: 



Mass 



Reducing: equivalenf; 

 in },ducose 



A. 1 : 1.8 



Strongly alk. 



0.21 



Brown 



0.075 gram 



B. 1 : 1.8 



,, ,, 



0.23 



>» 



074 „ 



C. 1 : 3.6 



Less ,, 



0.23 



Yellow 



0.073 ,, 



D. 1 : 5.4 Weakly alk. 0.17 White or 0.C61 



E. 1 : 5.4 „ „ 0.14 pale yellow 0.0G6 



