286 
DIETETIC PROPERTIES OF WHEAT. 
that from the opaque ripe flour had lost its tenacity and acquired a sweet taste ;■ 
whilst the translucent paste required more than four hours to arrive at the same 
state. 
By mixing the two kinds of flour with w^ater to a gruelly consistence, and 
then whipping the mixture with strips of wood or twigs, the strings of gluten 
adhering to these are far more tough and tenacious from the translucent than 
the opaque. This quality, as Dr. M‘Cormac mentions, the miller tests by simply 
chewing. 
If we take two kinds of flour,—some, the best, called by the miller “strong 
flour,” and some “poor and weak,”—and make each into a paste under exactly 
similar circumstances, we shall find that the paste of the former is by far the 
most firm and tenacious, aud also, when placed in a favourable atmosphere for 
undergoing change, it retains its tenacity for a much longer period. Add now 
to the paste of the strong flour a little infusion of bran, and this will cause it to 
become thin very far more rapidly than does the ivealcer paste ivitli xoater only. 
Again, add to the infusion of bran a little ahini., then mix it with the paste even 
of the weaker jioui\ and this will retain its consistence yet longer than the paste 
made with strong flour and water alone : the alum, combining with the soluble 
gluten and forming with it an insoluble compound, renders it inert. 
Wheat grain consists—putting aside inorganic matter, fat, and cellulose—of a 
mass of starchy granules interspersed by, if not enveloped in, an elastic net¬ 
work of nitrogenized matters which in the aggregate goes by the name of gluten. 
This gluten varies in character, dependent both on the state of the grain and 
also on the portion of the seed from which it is obtained. The interior portion 
yields a gluten less soluble and more tenacious; whilst the external portion, 
especially that immediately beneath the outer skin, contains nitrogen-yielding 
matter of diminished tenacity but increased solubility, acquiring the property, 
a.s shown by the infusion of bran, rapidly to change the starch into glucose. 
The valuable properties that bread possesses depend greatly on its mechanical 
structure; the dough, from being distended and blown out into a number of 
hollow cells or vesicles, is enabled to become cooked daring the baking, or 
“soaked,” as the baker calls it. That it retains the vesiculation through this 
process without collapsing, is due to the toughness of the gluten wdiich, rami¬ 
fying through the mass, holds it by its tenacity, suspended from the outer w^all 
of crust mechanically, and much in the same way as plaster is held together by 
hair. The lightness of the bread, therefore, depends on the strength or tenacity 
of the glutinous w^eb; whilst the common method of obtaining and disseminat¬ 
ing the carbonic acfd gas through the dough by vinous fermentation necessitates 
the exposure of the sponge to conditions very destructive of this. 
IVheats having the combined qualities of great strength of gluten with good 
flavour are exceptional and costly ; the most freely producing English w^heats, 
w'hilst possessing the latter, are deficient in the former. To remedy this, the 
miller adds to them a proportion of hard strong foreign grain ; but as this also 
commands a high price, the baker, wdio makes the commonest bread from very 
poor and home-grown flour, resorts to the use of alum, the question Avith him 
being w’hether to manufacture a white, light, well-baked bread which is saleable 
(without taking into consideration that it contains a compound of alumina and 
gluten not especially digestible), or a dark, heavy, uncookable mass, question- 
a.bly digestible and certainly not saleable. 
It is this constituent of the more external portion of the Avheat which renders 
the manufacture of bread from the whole meal so difiicult by the old process. 
Some medical authorities are of opinion that the hard branny portion causes an 
irritation of the bowmls, and that by the long-continued use of it this becomes 
chronic; but such an objection has been obviated by more than one process 
patented for unbranning A^heat, by removing merely the hard horny outer integu- 
