Syntlmis of Sugar \u:^ 



In B and E the separated gioimd solids were uuxvd h^rl.ilv but 

 Ihoroughly, and then warmed. In E the nias8 was mixed' and 

 ground with a glass pestle, while the reaction was taking place. 



P^urther investigation sjiowed, however, that to obtain maximum 

 polymerisation, with a minimum loss, quantities totalling not leu? 

 tlian 2 grams must be used. Otherwise the reaction is not so con»- 

 plete, and hence the low production of sugar alwve. Tlie rcKults 

 of three tests are> given, the second with a sample of (CH,0), oV>. 

 tained from thel Chemistry School, the first and tliird with samidec 

 prepared from a bulk sample supplied by rumin«:. Smith's, and 

 purified by sublimation. The proportions used were approxi- 

 mately 4 of (CHgO).-. to r Ba H^O.s. In all tliree. cases the residue 

 nvas brown, contained no formaldehyde, and whs weaklv alkaline. 



CH203 





BaH^Oa 



Ix)88 Of weijfht 



Reduction equivalent 



of residue in 



teruia of glucn«« 



1.25 gram 



- 



0.78 gram 



0.3P gram 



0.37 gram 



1.25 „ 



- 



0.78 „ 



0.33 ,. 



0.39 „ 



2.5 



- 



1.56 „ 



0.78 „ 



0.72 ,. 



lliis represents a polymerisation eipiivalent in terms of glucoee 

 -of 30 to 32%. Tlie maximum polymerisation in terms of glucose 

 obtained Avhen using boiling dilute formaldehyde was 20 to 3()'^o- 

 That is, in spite of the loss of formaldehyde vapour, more sugar i» 

 -obtained from solid metaformaldehyde and crystalline barium 

 hydrate than when the reaction is carried out with dilut<' solutions 

 in water. 



The last experiment (with 2.5 grams) was carried <>ut in a small 

 •distilling flask. Tlie distillate weighed 0.45 gram, so that appar- 

 ently at least J of the formaldehyde is lost as vapour. This would 

 increase the actual polymerisation value in terms of glucose to 

 •36%. 



Even if an excess of Barium hydrate is used, so that no trace of 

 formaldehyde^ remains in Mio resi<]ne, the filtered extract gives dis- 

 tinct aldehyde reactions, and hence pr<siniiably contains the biose 

 •sugar, glycollic aldeliyde. 



Paraformaldehyde', and ih^ pohjhydrnte. 

 The former was prepared by melting tlie latter an<l heating till 

 water vap.mr ceased to escape. Similar results were obtaine<l. but 

 the production of sugar was less, and the hydrate gave off more 

 -water vapour during the strongly exothermic reaction. 



