The Stourbridge Observer, Cradley Heath, Halesowen & District Chronicle.
Stourbridge, West Midlands, England, 1879-10-04 00:00:00

NATIONAL TRAINING SCHOOL OF
COOKERY.

Professor Church's third lecture on Monday on the
"Chemistry of Foods." at the National Training School
of Cookery, South Kensington, was occupied with a
consideration of the foods which are classed as heat-
givers, such as fats, starch, gums, &c.
After a general description of the group, the Pro-
fessor proceeded to the experimental consideration of
how the members of it are influenced by the processes
followed in cooking, and how their presence in food
material can be recognized. Referring first to starch,
he showed experimentally that the right way to
mix a starch is in cold water, and then put the
solution into very hot water. Starch is partly
turned into dextrine by being subject to a tempera-
tura which would nearly "roast it." 320 deg. F. will
completely change it. It was pointed out that, as at
a future lecture it would be requisite to distinguish
between starch and dextrine, the chemical tests should
be known. The starch test, iodine, can be easily
made by dissolving a crystal of iodine and adding some
spirits of wine. When iodine is added to a cold solu-
tion of starch a blue colour is produced ' • with a hot
solution the blue colour is not produced. Pro.
lessor Church took a small mass of wheaten flour
and kneaded it in water till he washed out all the
starch, the " heat-giving " portion of flour, leaving
the "flesh-forming " portion, which is called fibrin.
The fibrin in this case is not quite pure, as there
is a little fat and a little mineral matter also. The
starch test was applied to show that the part washed
away from flour on kneading really was starch. In
the change of starch to " dextrine " by roasting a
delicate fawn colour is seen to be formed. The effect
of iodine on dextrine is to give a reddish brown tinge
instead of a blue. The practical value of these tests is
to be shown in its bearings on cookery in a subse-
quent lecture. There is a great difference in solu-
bility in cold water between the crust o: a loaf and the
crumb. More of the crust than of the crumb will
dissolve.
Passing on to sugars, the differences between grape
sugar and cane sugar were spoken of by the professor,
and the tests for the one and the other were shown. With
cane sugar sulphuric acid gives a dark colour, but with
grape sugar it does not. The "sugar test" with com-
mon sugar gives a yellow precipitate. The value of
these tests is to be shown in future practical work.
Some experiments connected with oils were next
taken up. Oils dissolve in ether, but not in water.
If a mixture of ether and oil, however, is taken and
then mixed v. ith water, the oil and ether float on the
top with the water below. This fact has practical
bearings also. The albumenoids—fibrin, albumen
myosin, and casein—were briefly referred to, and
some of the conditions under which albumen
coagulates were illustrated. A temperature of
140dsg. F. effects coagulation, both with such albumen
as may be obtained from the juice of the turnip or
from the white of egg. The ordinary acids used in
cooking do not cause coagulation, though nitric acid
will. After a very rapid reference to fibrin, casein
was spoken off, and the effect of an acid, such as
acetic, was alluded to as producing a "a curd."
The conclusion of the lecture was occupied with a
brief reference to the way in which " heat-givers "
become the source of "force and energy" in the body.
They are over 100 grown-up pupils attending the lec-
tures.

RELICS OF LAPEROUSE'S EXPEDITION.—The Sydney
Morning Herald of August 14 says :—" Attention has
been directed to the fact of two of the cannon which
were part of the armament of one of Lap6rouse's ships
having been found imbedded in a coral reef on the
coast of Vanikoro, We understand, from a gentle-
man who saw them, that in his opinion they might be
easily recovered if the reef were shattered by a
charge or two of dynamite. Such interesting relics
would surely be an attraction during the Exhibi-
tion, and no doubt, if the matter were suggested to
Commodore Wilson, he would give instructions to
the commanders of some of the vessels cruising
among the South Sea Islands to take steps to recover
them."

"Mr LOVE TO THEM ALL! '—As Sheridan Knowles
was walking one day with a brother dramatist. he was
accosted by a gentleman in these terms :—"You're a
pretty fellow, Knowles! After fixing your own day
and hour to dine with us, you never made your appear.
ance !" "I couldn't help it, upon my honour ! " replied
Knowles. "How are you all at home?" "Oh, quite
well, thank you. But, come now, will you name
another day and keep your word ?" "I will —sure I
will." "Well, what day? Shall we say Thursday
"Yes, Thursday be it. "At six?" "At
be there punctually. My love to 'em all."
The friend departed, and Knowles, relinking his arm
with that of Bernard, said, "Who's that chap?" not
having the least idea of the name or residence of the
man he had promised to dine with, or the intelesting
family to whom he had otoit 1,