20 
SELECTED ARTICLES. 
grains would have appeared themselves cracked, but retaining 
their form and ordinary dimensions, fig. 2, b ; for in order 
that an integument shall split in distending, it is necessary 
that the grain should be plunged in a humid atmosphere, so 
that the soluble substance shall find a solvent at the favor- 
able instant. Torrefaction could only affect them at the instant 
they were formed into globules, for its effects are well evinced 
upon the surface of the spheres, less so immediately beneath, 
and not at all in the centre. Now when an attempt is made 
to account for the formation of such globules, it must be 
admitted that the moist fecula has been pressed in a kind of 
strainer, that it is moulded by the perforations, and that after 
having passed through, it falls upon a surface heated at least to 
100° R. The size of the globules, for this reason, depends en- 
tirely upon the diameter of the perforations. The varieties of 
sago, therefore, only indicate the difference of the mechanical 
methods employed. 
Wheat Fecula. 
( Triticum sativum, L.) PI. fig. 4. The greater number and 
the largest grains of this fecula do not exceed ^ of a milli- 
metre; they are spherical, and commingled with patulous 
torn integuments, which depend upon the grains of fecula 
which have been broken by the mill. They are much more 
shining, rounder, and better preserved, if extracted from the 
seed when still a little green, and not allowed to dry upon the 
stalk. It is extracted in the following manner, for the use of 
linen manufacturers, who prefer it as starch for glossing fine 
linen. The starchmakers place the farina, coarsely powdered, 
in large vats, without even taking the trouble to separate the 
bran; they use also coarse meal and damaged wheat. They 
mix the farina with a certain quantity of water, to which is 
added a small quantity of acid water, the product of a preced- 
ing operation. The sugar and gluten contained in the farina 
speedily react upon each other, to produce, in the first place, 
alcohol and carbonic acid, then acetic acid, which dissolves 
the remainder of the gluten. This is what at first was called 
