1915] Arthur W. Thomas 381 



by means of its depression of the freezing point of water. Their 

 experimental figure for the molecular weight was 6221, which 

 agreed most closely with the formula (Ci2H2oOio)2o> the molecular 

 weight of which is 6480. They adhered to their theory that 

 starch was composed of five amylin groups and represented the 

 hydrolysis by these equations : 



First, (Ci2H2oOio)20 + HsO^ Ci2H220u- (Ci2H2oOio)i9 



Amylin 



Last, (Ci2H2oOio)20 + 19^20-^ (Ci2H220ii)i9-Ci2H2oOio 



Maltodextrin 



Brown and Morris concluded, from the results of their later 

 work, that the maltodextrins split into smaller substances of varied 

 composition. Two different maltodextrins were isolated by the 

 authors, one with the formula (Ci2H2oOio)2*Ci2H220ii (malto- 

 dextrin) and another with the formula (Ci2H2oOio)6"Ci2H220ii 

 (amylodextrin). 



Scheibler and Mittlemeier,^ in 1890, discussed the hydrolytic 

 products of starch and dextrin. One noteworthy feature of their 

 paper was the preparation of the hydrazone of a commercial dex- 

 trin which, upon analysis, was found to have a composition indi- 

 cated by the formula, C96H162OS0N2HC6H5. This corresponds 

 with (C6Hio05)i6. which is somewhat similar to the amylodextrin 

 reported by Brown and Morris. 



Lintner and DuelF^ claimed that, in its hydrolysis, the complex 

 starch molecule split first into amylodextrin (better known at the 

 present time as soluble starch), and that this soluble starch then 

 broke down into three molecules of erythrodextrin, which in turn 

 split into three molecules of achroodextrin, the latter Splitting into 

 iso-maltose, iso-maltose changing to maltose. They determined the 

 molecular weight of these substances by means of the freezing- 

 point method of Raoult, with the f ollowing results : 



Soluble starch 17,496 (CiaHaoOjo)« 



Erythrodextrin 5,850 ( Ci^HooGic) « • H2O 



Achroodextrin 1,962 {Ci2^2<P 10)^-^20 



In 1897 a formula only one quarter as great as that of Lintner 



9 Scheibler and Mittlemeier : Berichte, 1890, xxiii, p. 3060. 

 1° Lintner and Duell : Berichte, 1893, xxvi, p. 2533. 



