37 
maltose. The reason of this is that maltose can be made to yield 
alcohol by fermentation, while starch cannot. Now, the conversion of 
starch into maltose is effected by one of a peculiar class of bodies, called 
ferments, whose very compo — and mode of action is still imperfectly 
understood. In the case of s m the conversion into maltose 
effected by a ferment called ee 
But a ferment of the nature of АА is, there is reason to believe, 
very widely distributed in plants, and is by no means confined to the 
seeds of barley. Diastatic fermen ts have been found in leaves and 
shoots, and it seems probable “ that a ferment of. this kind is present in 
all living plant cells.^ Few an have been more carefully investigated 
than the chemistry of malting, and it might be supposed that the 
chemical results of the change by which starch is converted by means 
of a ea rt ferment into a soluble sugar D be thoroughly under- 
stood. s is, however, far from being the cas 
сап be no doubt that in the case of Е nur barley the 
resultant is maltose. This is not, however, apparently, much met with 
in plants. What is met with is a substance да ,sintplér constitution, 
ealled variously glucose, dextrose, or grape It is * widely dis- 
T 
* tributed throughout the vegetable Mani beitig especially abundant 
* in the juice of 1 ripe sweet pirate tue name grape sugar =. derived 
* from its occurrence in considerable quantity in ripe а 
е is asked as to the origin of glucose he can give no ye ene 
r 
It appears that diastase has no further effect on starch-sugar after it 
has produced it from starch, but that dilute acids have ; and as dilute 
acids abound in plants we can easily understand that the stareh in 
plants may yield ае = that this may in turn be bro ken up 
fast as formed. Here, however, the chemists fail us; they have not 
yet made up their mind as to "what 1 is the exact result of the action of 
dilute acids on starch-s 
“ Although," remar aE. Armstrong ‘and Groves, "there can be little 
“ doubt that the final product of “the action of acids on starch is not 
* merely sucrodextrose [glucose], as has been nd generally supposed, 
Still, Soph chemists n give no cid theoretical account of - 
the origin of glucose in "the plant, it is a substance onl 
importance to starch, of which there cannot be the t€ doubt, 
from the chemical point of view, that it is the direct deriva 
Leaving glucose for a moment, we may turn our ilu to cane- 
sugar. While the former is a migra product, destined to afford 
materialfor the building up of tissues, the latter, as Sachs correctly 
points out is al " st or some future effort of 
growth on alarge scale, sueh as the process of flowering. Yet it is 
singular that it is twi soluble as glucose. Nev ucose 
seems to be t called the sugar “currency " of the plant 
economy, and cane-sugar only the * bullion” or banking reserve. The 
botanist is quite clear as to what happens in a eane-sugar This 
is Sachs’ account :—“ h is assimi in the leaves of the Beet ; 
“ їп the petioles it is found again in the foris of glucose. This 
* glucose eti enters the growing” and swelling root, and is trans- 
* formed into cane-sugar in its parenchyma.” Тһе parallel processes 
sugar-cane seem to have been’ little studied. "Thé following note 
is therefore reprinted from the Proceedings of the Agricultural and 
Horticultural = of India for July 1890 :— 
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