180 A. J. Etvart: 



10 per cent. 31.5 per cent. Aniount req. 



Water Ca formate CHqO of 4.!) per cent. KHO 



A — 750 - 15 c.c. - 15 c c. - 27.0 c.c. 



B— 750' - 25 c.c. - ] 5 c.c. - 29.5 c.c. 



10 c.c. of A were diluted to 50 c.c. with 10% NHJ^O. and titrated 

 :against 50 c.c. of Pavy's solution (8.316 grams copper sulphate 

 -per litre). 



34.7 c.c. neutralised 50 c.c. of Pavy. There was no increase in 

 the reducing power after boiling with citric acid. 



After heating with 1 drop of HCl., S^.o c.c. reduced 50 c.c. of Pavy 



After heating with 5 drop.s of HCl., 35.-4 c.c. = 50 of Pavy. 



After heating with 10 drops, 44.5 c.c. decolorised 50 c.c. of Pavy. 



Hence a trace of non-reducing sugar may be present capable of 

 inversion by HCl, but excess of HCl causes the decomposition of 

 some of the sugar. 



Repeating A and B several times, the maximal reducing action 

 •obtained was 33.5 c.c. =50 c.c. Pavy = 0.025 gram glucose, and, 

 therefore, the total bulk of 805 c.c. of syrup had a total reducing 

 power equivalent to 1.348 gram of glucose. Since 15c.c. of 51.5% 

 CH::0 were used ; in? terms of glucose this would represent a sugar 

 polymerisation of 29%. 



In a test with caustic soda alone, 35% caustic soda was run into 

 boiling 31.5% CH^O. A yellow tinge appeared at once, but to 

 neutralise all the formaldehyde 25 c.c. of 31.5% CHoO required 

 14.8 c.c. of 35% NaHO. As 14.8 c.c. are equivalent to 23 c.c. of 

 CH5O, this represents a theoretical polymerisation of 8%. The 

 liquid contained reducing sugar equivalent to 0.13 gram of glucose, 

 which represents a polymerisation in terms of glucose of 2%. 

 Owing to tlie strength of the alkali used, however, much of the 

 «ugar formed is caramelised. 



21ie action of alkali'- s on the polymers of formal dthyde. 



The concentrated aqneous solution of CH.^O is supposed not only to 



C) _ Y\ 



C(mtain volatile CH.^0, but also hydrates such ms CH.^_.j_tt, and 



(CH/,/^0(0H)2. The latter is a non-volatile polyhydrate which 

 leaves a waxy' solid on complete evaporation, supposed to be difor- 

 maldehyde, " paraformaldeliyde " (CHoO)^. The better known 

 Iriformaldehyde or metaformaldehyde (CHoO)g is stated to be dis- 

 "tinffuished from diformaldehvde by its subliming just over 100°C., 

 whereas its M.P. is 171-172 "C.. and by its insolubility in water, 

 alcohol and ether. 



