Manual for the physiological laboratory / by Vincent Harris and D'Arcy Power.

  • Harris, Vincent.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Manual for the physiological laboratory / by Vincent Harris and D'Arcy Power. Source: Wellcome Collection.

    214/360 (page 204)
    OILS AND FATS. Oils and fats are neutral substances, with the composition of a compound ether, glycerine, CsHgfOH);] being the alcohol: They are lighter than water ; specific gravity '91 to 94; They give a greasy stain on paper; They are insoluble in w^ater; but are soluble in ether, chloroform, benzol, turpentine, or alcohol. The chief fats of the body are : Triolein, angfOCigk^O),, is the most soluble of the fats, being soluble in both cold and hot alcohol or ether, and remaining fluid at 3° C. Tristearin, C3Hg(OCi8H;^50)3, is the most insoluble, not dis- solving in cold alcohol or ether, and not melting at a temperature below 53^ C. Tripalmitin, C3Hg(OCi6H3iO)3, is midway in solubility and melting point between the other two. Glycerine.—A sweet-tasted viscid liquid, soluble in water and in alcohol; insoluble in ether. Test.—Heat a little glycerine in a test-tube with some solid acid potassium sulphate; acrolein, a body of pungent smell, is produced (C3H803-2HoO=C3H40). Olive Oil, containing triolein or glycerine trioleate : 3(Ci8H3:A) C3H5 (i.) Shake up a few drops of olive oil in a test-tube v/ith water, and then allow it to stand; note that no emulsion or breaking up into \evy minute particles which do not run together takes place. Add ether, and shake the test-tube ; note the solution of the oil in that reagent, (ii.) To 10 cc. of a weak solution of potassium carbonate add a few drops of olive oil in a suitable test-tube, and shake