248 
STARCH, ITS VARIETIES AND CHANGES. 
which the ruff came into vogue. Starch was brought into use in England 
by a Mrs. Dingen van Plesse in 1564; and it was considered an im¬ 
provement of such importance in the laundry, that it was elevated at 
once into an ‘art,’ in which Mrs. Dingen van Plesse gave lessons at 
the enormous premium of five guineas. At first the starch was of the 
common dead-white hue, but in process of time various glowing dyes 
were introduced, so as to give increased effect to the ruff by the tints it 
was thus made to shed upon the face. There was a yellow dye dis¬ 
covered by the notorious Airs. Turner, who was implicated in the murder 
of Sir Thomas Overbury; but it was dismissed with abhorrence by the 
fashionable world, says Dr. Drake, when its ingenious inventor was 
executed at Tyburn in a ruff of her favorite tint.” 
Iodine is a very delicate test for starch, forming with it a 
blue compound—the iodide of amylum. Its chemical compo¬ 
sition is given as C 24 H 20 O 20 . The granules are irregularly 
shaped, and they vary in size, from the ^^th t0 Wooth 
part of an inch in diameter. This variation in shape and 
size is seen in every species of plant yielding it. Under the 
microscope they appear to possess a central nucleus, called 
amidine or dextrine , which is surrounded by an envelope. This 
envelope is insoluble in cold water, but it expands and at 
length bursts as heat is applied to it. Acids and fermentation 
also produce the same effect. From this circumstance we 
are enabled to understand the benefit derived from steaming 
or cooking of the farinaceous food of animals, as well as, at 
least in part, the action of the stomach on it. 
The following table gives the quantities of starch in 100 
parts of the various kinds of grain, tubers, &c. 
Ilice 
. 74 parts. 
Beans . 
. 36 parts. 
Maize . 
. GO 
33 
Lentils . 
. 35 „ 
Wheat . 
. 59 
33 
Parsnips 
• 17 „ 
Rye . 
. 51 
31 
Potatoes 
. 15 „ 
Buckwheat . 
. 50 
33 
Mangel-wurzel 
. 12 „ 
Barley . 
. 48 
33 
Carrots . 
• 11 „ 
Oats 
. 39 
33 
Turnips . 
• 10 „ 
Peas 
. 37 
33 
Cabbage 
• 4 „ 
Changes of Starch. 
Starch, by the application of heat to it for some hours, 
the temperature being from 250° to 300° Fahr., becomes 
converted into dextrine. The change is said to be only a 
molecular one, and probably it is the result merely of the 
bursting of the envelope. 
Dextrine is of an amber colour, soluble in cold water, and 
largely used by calico printers for stiffening their goods, 
under the name of British gum. The larger quantity, perhaps, 
is obtained from potato-starch. 
