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Gum and sugar, excluding the different propor- 
tions of water they may contain, afford nearly the 
same elements by analysis ; and starch differs from 
them only in containing a little more carbon. The 
peculiar properties of gum and sugar must depend 
chiefly upon the different arrangement, or degree 
of condensation of their elements ; and it would 
be natural to conceive, from the composition of 
these bodies, as well as that of starch, that all three 
would be easily convertible one into the other ; 
which is actually the case. 
At the time of the ripening of corn, the sac- 
charine matter in the grain, and that carried from 
the sap vessels into the grain, become coagulated, 
probably simply by losing water, and forms starch. 
And in the process of malting, the converse change 
occurs. The starch of grain is converted into 
sugar. As there is a little absorption of oxygen e, 
and a formation of carbonic acid in this case, it is 
likely that the starch loses a little carbon, which 
combines with the oxygene to form carbonic acid ; 
and probably the oxygene tends to acidify the 
gluten of the grain, and thus breaks down the 
texture of the starch ; gives a new arrangement to 
its elements, and renders it soluble in water. 
Mr. Cruikshank, by exposing syrup to a sub- 
stance named phosphuret of lime, which has a great 
tendency to decompose water, converted a part of 
the sugar into a matter analogous to mucilage. 
And M. Kirchhoff, recently, has converted starch 
into sugar by a very simple process, that of 
boiling in very diluted sulphuric acid. The pro- 
portions are 100 parts of starch, 400 parts of 
