246 
STARCH, ITS VARIETIES AND CHANGES. 
so enormously increased that at one single print works near Manchester 
more than 300 tons are used annually. In nature starch is often found 
associated with poisonous matters—in the arum with an acrid substance 
—and in the mannihot with prussic acid ; but the natives of Guiana and 
the West Indies have found out that by heating the roots of the mannihot 
the prussic acid is dissipated, and then the tapioca obtained is harmless.” 
We have lately seen a very simple but highly ingenious 
and effective machine, invented by Mr. H. Martin, of Eden- 
bridge, for separating starch from the flour of wheat, by 
mechanical means alone; that is, without setting up the 
fermentative process in it. By the use of this machine, not 
only is there no loss of material, but a considerable saving of 
time, since less than hours suffice to effect what required 
days by the old process, while the quantity of starch ob¬ 
tained is also much greater. Ordinarily from wheat this 
amounts to from 42 to 44 per cent., and by the 
machine, from wheaten flour, as much as 75 per cent, has 
been procured. The plan, we need hardly say, is patented, 
but it essentially consists in making a paste of the flour, and 
causing grooved rollers to pass backwards and forwards over 
it, while small streams or jets of water play continuously on 
it, so as to carry off the starch as it is separated into a fit 
receptacle. The gluten, the other essential constituent of 
wheat, is thus of course left behind, and when in a moist 
state, this is sometimes as much as 2 5 per cent. It 
is very pure ; and it is principally for this substance that the 
invention is worked. By drying, it loses more than half its 
weight; but if baked, it resembles in appearance very light 
and porous bread, and in this state it may be kept with care 
for almost an indefinite period. We saw some twelve months 
old, which was perfectly good. In taste, after it had been masti¬ 
cated for alittle time, it strongly resembled animal matter. There 
is every reason to believe—at least it appears so to us—that 
when this process is generally known, it will become the one 
resorted to for the purpose of separating these two principles, 
starch and gluten, the one from the other, since it has in its 
favour both the saving of time and the obtainment of a larger 
amount of produce, especially as far as bran and gluten are 
concerned, while the last named is nearly equal in value to 
the starch obtained. 
When we were first shown the gluten, we could not refrain 
from asking ourselves the question, would it not have been 
wiser in the feeding of animals, instead of giving to them that 
kind of provender which is conducive to the laying on of fat, 
and by doing which too often a debilitated state of the system 
is induced, thus favouring the development of disease, to have 
