308 Extracts from, the Journals. [Oct., 



By the process of malting, barley undergoes a peculiar change, 

 that of germination. Barley is steeped in water, and then ex- 

 posed to air in thick layers, at a moderate temperature, and fre- 

 quently turned; this produces germination of the seed; the process 

 is then checked by drying in a current of warm air as soon as the 

 sprouts have acquired a length about equal to that of the seeds; 

 they now constitute malt. The essential change which is caused 

 by "these processes, so far as regards our present purpose, is the 

 production of a peculiar substance, diastase, in all probability at 

 the expense of the fibrin of the grain, by which the amylaceous 

 portion is partly converted into dextrine, (a modification of starch) 

 and finally into sugar. 



During the process there is a considerable evolution of car- 

 bonic acid, produced from the carbonaceous portions of the barley, 

 uniting with the oxygen of the air; this consumption, and other 

 losses during the process, by steeping, &c., cause a diminution in 

 the weight of the grain, amounting to about 13 per cent. After 

 malting, the two substances thus stand in relation to their proxi- 

 mate constituents: 



Barley. Malt. 

 Gluten _ - - 3 1 



Sugar - - - - 4 16 



Gum - - - - 5 14 



Starch - - - - 88 69 



100 100 



The total loss which barley sustains by malting, (Thompson is 

 quoted,) amounts to more than ]9 per cent. But as bailey con- 

 tains 13.1 per cent, and malt 7.06 of water, 6 parts out of the 19 

 per cent are water, so that there is actually only lost 13 solid 

 matter. Thus, water, 6; saline matter, 0.41; organic matter, 

 12 52=19. The elementary constitution of malt, is as follows: 

 C 44.78, H 7.06, N 1.62, 44.76, Ash 1.77=100. 



In a few words then, by malting, in reference to barley: the 

 soluble salts are much diminished, so that a larger quantity of the 

 former grain would be required to produce the salts necessary for 

 animal "purposes. The quantity of nitrogen is also inferior, and 

 hence in equal weights the nutritive power of _malt must be less 

 than that, of barley. The carbon is also lessened in quantity, 

 while the starch and gum is diminished, and the sugar increased. 



Havino- briefly considered the chemical difference w^hich exists 

 between malt and barley, w^e return to Dr. Thompson's practical 

 experiments. These were performed on two lean bullocks, three 

 years of age, and as near as possible the same in constitution. 

 The weight of one bullock, A, was 9 cwt. 7 lbs.; of the other, 



