It is known how difficult it is to
isolate and study albuminous substances. The following is the method of
obtaining and studying cerealine. Take the raw embryous membrane, prepared
as stated, steep it for an hour in spirits of wine diluted with twice its
volume of water, and renew this liquid several times until the dextrine,
glucose, coloring matters, etc., have been completely removed. The
membranes should now be pressed and cast into a quantity of water
sufficient to make a fluid paste of them, squeeze out the mixture,
filter the liquid obtained, and this liquid will contain the cerealine
sufficiently pure to be studied in its effects. Its principal properties
are: The liquid evaporated at a low temperature produces an amorphous,
rough mass nearly colorless, and almost entirely soluble in distilled
water; this solution coagulates between 158 deg. and 167 deg. Fah., and the
coagulum is insoluble in acids and weak alkalies; the solution is
precipitated by all diluted acids, by phosphoric acid at all the degrees of
hydration, and even by a current of carbonic acid. All these precipitates
redissolve with an excess of acid, sulphuric acid excepted. Concentrated
sulphuric acid forms an insoluble downy white precipitate, and the
concentrated vegetable acids, with the exception of tannic acid, do not
determine any precipitate.
Pages:
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34