172 A. J.' Eivart: 



tetroses or hexoses were formed directly from biose produced in this- 

 «vay, the percentage polymerization by weight would be the 

 same. If, however, pentoses and hexoses were formed by the direct 

 linking of formaldehyde to the glycollic aldehyde, without further 

 xjroduction of formates and methyl alcohol, the pohonerisation 

 ratio for pentose would be 9 :5 (45%), and for glucose would be 

 10 :6 (60%). If a dissaccharide were produced, the maximum 

 ratio would be 16: 12, i.e., 75%. 



A monovalent alkali such as sodium hydrate can react with single 

 molecules of C^,H^Oo, pi-oducing sodium formate and methyl alcohol, 

 and will only produce a liiose when 2 of sodium hydrate react' with 

 2 of CgHjO,, with a third molecule interpolated. The chance for 

 this grouping is not more than lialf what it is in the case of a diva- 

 lent alkali, wliei'e a single molecule react)? with not less than 2 mole- 

 cules of C,H_,0,. 



Methods. — The same result is not produced wlien the licjuids are- 

 mixed cold, and then heated, as when the sodium hydrate is run into 

 the boiling liquid. Ihus 250 c.c. of water, with 5 c.c. of 10% 

 calcium formate and 4 c.c. of 25.2% formaldehyde, after raising 

 to the boiling point required, 7.2 c.c. of 3.5% NaHO to complete- 

 the reaction. If mixed cold with 7 c.c. of sodium hydrate, on rais- 

 ing to the boiling point a further addition of 0.4 c.c. of NaHO was 

 required to complete the reaction. If mixed cold with 7 c.c. NaHO, 

 and kept for 15 days at 15° L., on raising to the boiling point, the 

 addition of a further 1.2 c.c. of NaHO is required to complete the 

 reaction , And remove all CH^O. Hence at low temperatures more 

 formate is produced and less formaldehyde is polymerised to sugar, 

 so that more soda is required to remove all the formaldehyde. 



In carrying out estimations, a preliminary test was in each case- 

 carried out in an open beaker. The amount of sodium hydrate re- 

 quired was less than the full amount by the amount of CH^O lost 

 during the boiling. The same amounts of CH.,0; water and cal- 

 cium, formate, were then placed in a flask fitted with a condensing 

 apparatus, so that the condensed steam washed back the escaping 

 formaldehyde. Tlie amount of sodium hydrate previously noted 

 was tlien run in from a burette fitted to the cork, as i-apidly as 

 was possible without causing too violent ebullition. 



The yellow tinge which indicates the completion of tlie reaction 

 appears slowly with very dilute solutions, and the preliminary test 

 must be checked by smell as well as colour. With strong solutions 

 the yellow colour is produced before the reaction is completed, if 



