Polymerization of Forinaldeliyde. 201 



while kept heated to boiling point one and a-lialf volumes of 12% 

 sodium hydrate are added. The latter portions are added slowly, 

 and if necessary a few drops additional. A white precipitate is 

 formed at first, with each addition of sodium hydrate, which re- 

 dissolves slowly, the liquid remaining alkaline. With the addition 

 of the last few drops, the liquid suddenly clears, become pale 

 yellow, ceases to smell of formaldehyde, but develops a slight cara- 

 mel smell, and is neutral. If an excess of sodium hydrate is added, 

 the liquid turns brown, and a precipitate may form, but it may be 

 neutralized with a drop or two of acid. On cooling and standing, 

 a white crystalline solid separates, which is insoluble in absolute 

 alcohol, and practically so in cold water. On heating it chars, 

 glow^s and leaves a bulky chalk ash. It is, therefore, an organic 

 calcium compound. The filtrate gives all the tests for a reducing 

 hexose sugar. It also gives red with picric acid, and sodium 

 hydrate, and gives a caramel smell, and darkens when warmed with 

 sulphuric acid. It gives the keto-hexose reaction, with resorcin and 

 HCl. With phenylhydrazin and sodium acetate, it gives a golden 

 yellow imperfectly crystalline osazone. The liquid showed a feeble 

 laevo rotation. 



The diluted liquid, after adding yeast and Pasteur's Solution, 

 keeping at 30°C. for three days, and distilling, gave a product 

 containing an appreciable quantity of alcohol, and giving the 

 iodoform test readily. The sugars are, therefore, in part at least 

 fermentable. 



The following procedure was adopted to separate the different 

 products : — 



The original syrup contains several compounds. After no more 

 of the insoluble calcium compounds would crystallize out, the 

 syrup Avas filtered, and twice its volume of absolute alcohol added. 

 A colourless viscid liquid separates and falls to the bottom. After 

 washing this with alcohol it becomes a white viscous solid. On 

 adding water it partly dissolves and a white crystalline solid 

 separates, which when heated chars with a slight caramel odour, and 

 leaves an alkaline ash containing CaO and CaC03. The filtrate, 

 after the addition of water, gives a strong reduction with Fehling's 

 test. On evaporating nearly to dryness, and cooling, a white crys- 

 talline solid separates, Avhich is an organic sodium salt, and the 

 syrup contains sugar. It yields a glucosazone, but gives only a 

 faint reaction with resorcin and HCl., and appears to contain more 

 glucose than levulose. 



