Si/vthesi8 of Sugar ]7;j: 



the soda is added more rapidly than the formic acid is pro- 

 duced. With a little practice these two sources of error arc ^asilv 

 avoided. 



A solution containing 250 c.c. of water, 5 c.c. of 10% calcium- 

 formate, and 5 c.c. of 31.5% of formaldehyde required 9.6 c.c. of 

 3.5% sodium hydrate, and required 25.8 c.c. of aoda when no 

 calcium formate was present. If no polymerisation had taken 

 place, then; the equation would be — 



2 CH20 + 2NaHO =CH,,HO + N;i CO OH 



i.e., 60 grams *of formaldehyde are required to neutralise 40 grams 

 of sodium hydrate (or 38 grams of calcium hydrate.*). 



3 grams of CH<^0 are contained in ..,- c.c. of 31.5^^ solution. 



2 X 1 00 

 3 grams of NaHO are contained in " . c.c. of 3.5 solution. 



0. 



/. Ic.c. of 31.5%CH./):=6c.c. of 3.5%NhHO. 



In the experiment 9.6 c.c. of soda were required, which reprebeiits- 

 1.6 c.c. of CH^O. Hence of the 5 c.c. of formaldehyde used 3.4' 

 c.c. were theoretically polymerised to sugar. In this way, the appar- 

 ent percentage polymerisation can be calculated under varying con- 

 ditions, and with various concentrations, as thus :— 



;j^j2^<_ -CA-V*^*-*^ c.c. of IOT; CO. of 31.. V. p.c. of 3..^:. Per rent, of rH,0 



Water j>nfx^ OH () NaHO rtMiuind }>olynieriie*l 



250 C.C. - 5.0 - 5.0 - l*.«e.c. - as 



250 c.c. - 0.0 - 5.0 - 27.HC.C. - 8 



In addition to sugar, however, small amounts of by-products; 

 may appear. Thus perceptible amounts of dihydroxyacetone are 

 produced when formaldehyde is polymerised to sugar by boiline^ 

 wath calcium carbonate.* Allowing for this possibility, the per- 

 centage polymerisation to sugar is between the theoretical maximum 

 of 75% for the disaccharide and 60% for hexo.se. 



The influence of the concentration of calcium formate present 

 was found by varying the amount added, while keeping the water 

 and formaldehyde constant. Five c.c. of 31.5% (^H«0 were addecf 

 to 250 c.c of calcium formate and water. 



The soda first reacts with the caleiuin formate, forming calcium- 

 hydrate and sodium formate. The calcium hydrate reacts with the 



4. H. and A. Culer. Ber.d. D. Bot. (les. nWS, 3». pp. 'M. =«• 



