A Manual of the Chemistry of the Carbon Compounds

'MIS CARBON COMl'OVNlUf. 4111)
substaucc. It is tbo best material for the preparation of ghdawic
acid (see page 233).
Blood-Fibrin is dissolved in the blood, but coagulates as soon as
the blood leaves the living organism, and forms, together with the
red blood-globules, the blood-coagnlnm. Bnt if blood be run from
the veins into a concentrated solution of glauber-salt, the fibrin
remains in solution, from which, after filtration, it is precipitated by
adding common salt.
Mu$cle-Fibnn or Myoslu.—To obtain this body, finely chopped
meat is exhausted with cold water, and the residue triturated with a
solution containing not more than 10 per cent of common salt. The
inueilagenous solution thus obtained is precipitated by adding more
salt, myosin being only soluble in a dilute solution of salt, but
neither in a concentrated one nor in pure water.
Gkfoidin is contained in blood-serum, and obtained as a granular
precipitate by diluting the serum with ten parts of water, and passing
a rapid current of carbon dioxide through the solution. It dissolves
in very dilute salt-solutions, and in. water containing a trace of an
acid or alkali, but becomes insoluble when heated with water to 70°.
Vitcllin occurs in the yolk of eggs, and is obtained by treating the
yolk 'with ether to remove fats and the colouring matter; it is a
white granular powder, which is soluble in salt solutions. It has
great resemblance with rayosiu, from which it differs Ly not being
precipitated by saturating the solution with salt
Syntmrin is produced by the action of weak hydrochloric acid on
myosin or tbat of strong acid on any other proteid. When the
solution thus formed is diluted with water, syntom'n is precipitated
in combination with the acid. When this compound is decomposed
by a dilute solution of sodium carbonate, syntouin goes in solution.
It is insoluble in water, bnt dissolves in acids and in alkaline
carbonates.
Vegetable Fibrin.—"When wheatcn flour is made into a paste with
water, and this is tied up into a cloth and washed with water as
long as starch pusses through, an adhesive, elastic substance is left
behind, which is called gluten, and consists o£ a mixture of vegetable
fibrin and gliadin. Tlicy are separated by dissolving the gliadui in
alcohol and treating the residual fibrin with ether to remove fat.
Vegetable fibrin is a soft, elastic mass, dissolving in veiy weak acids,
and alkalis, from which it is precipitated by salts.
Gliadin or Vegetable Glne is an adhesive substance, which dries up
to a horny, fcvauslncent mass, resembling glue. It is insoluble in
water, bnt dissolves in alcohol, acetic acid and dilute alkalis.
Hamarjlobin forms the principal port of the red Hood-globule."!.
It is soluble in water; whon alcohol is added to this solution, and
the liquid is left to stand at a temperature below 0°, hremaglobin
separates out in the crystalline state, the form of the crystals varying
with the animals. After being dried over sulphuric acid at a
temperature not above 0", it forms a brick-red powder.