670 TRANSACTIONS OF SECTION B. 



to connect the composition by volume, which he knew, with the composition in 

 terms of atoms. 



Knowing various cases of combination of two elements in more than one 

 proportion, he continued to apply the atomic theory. He regartled sulphurous 

 acid virtually as SO, and sulphuric acid as SO^. He recognised five oxides of 

 nitrogen, which he regarded as NO, KOj, IsOg, NO^, and NO^. In the Wilde 

 Lecture for 1908, on the 'Phyfiical Aspects of the Atomic Theory,'^ Larmor 

 expresses the 'Daltonian principle 'in the words 'a definite m ilecule for each 

 substance.' This principle, which is certainlj' common to the various systems of 

 chemistry of the nineteenth century, was adopted by William Hi,:rg-ius as early as 

 the year 1789, 



8. The Action of the Enzymes of Malt on Ungerminated Cereals. 

 By Julian L. Baker, F.I.G., and H. F. E. Hulton. 



In a communication recently made on the strength of wheat flours* we recorded 

 experiments showing that when a flour is doughed the evolution of carbonic acid 

 under standard conditions bears no relation to the diastatic activity as expressed 

 in degrees Lintner. When, however, a minute quantity of malt is added to the 

 dough the volume of gas evolved during the fermentation is increased in inverse 

 ratio to that originally given off; and in those cases where the original gas 

 production was low it is very largely increased. 



J. S. Ford and J. M. Guthrie ' in their recent work have shown that the 

 filtrate obtained by digesting an aqueous suspension of flour in presence of 



fapain is enabled to saccharify a greatly increased quantity of soluble starch, 

 n view of this work it would appear at least probable that the increased gas 

 production obtainable from dough by the use of malt might be due to the pro- 

 teolytic enzyme known to exist in malt, which by liberating more diastase, or 

 owing to its protection of that already present, renders more of this enzyme 

 available for the hydrolysis of the starch in flour. Ford and Guthrie (loc. cit.) 

 measured the saccharifying effect alone; but the enhanced gas production observ- 

 able in dough containing a trace of malt must be due to an enzyme capable of 

 attacking the starch of the flour itself, which, of course, is fund imentally dif- 

 ferent from soluble starch. This led us to investigate the combined action of 

 the enzymes in barley and malt upon soluble starch and starch paste, with the 

 liope of throwing some light upon the nature of the activities involved. 



If barley, when digested with malt — a substance which coatains both a 

 starch-liquefying and proteolytic enzyme — were to yield a filtrate more diastatic 

 in its activity than that obtainable from the barley alone, then presumably this 

 enhanced activity of barley extract might be due to the action of the pro- 

 teolyst in the malt upon the barley. The nature of this increase, if any, could 

 be investigated by comparing its action upon soluble starch and starch paste, 

 pince liquefying diastase, if liberated, cannot be supposed to increase the amount 

 of maltose produced from soluble starch, but would materially help the saccha- 

 rification of starch paste; on tlie other hand, if saccharifying diastase were the 

 one formed, then the conversion of starch paste would probably not be facilitated, 

 but soluble starch would be further sacchai-ified and yield more ma'tose. 



Finally ground malt and barley were separately extracted at the rate of 

 five grams per 100 c.c. At the same time a mixture of 2^ grams of malt and 

 '2| grams of barley was also digested with 100 c.c. of water. Filtrates from the.se 

 three extractions were examined as regards their action upon 2 per cent, soluble 

 Btarch and 2 per cent, starch paste for periods of one and two hours, at a tempe- 

 rature of 21°, the results being expressed as grams of maltose formed per gram of 

 barley, malt, and mixture of the two. Precautions were takeo t? jfeep the pro- 



' Manchester ifi^moirs, 1908, 52, No. 10, p. 10, 

 « /. Soo. C/iem,. Jnd., 1908, 27, 368. 

 ' </. I'h'it, (if Sremiiifj, J 908, 14, 61. 



