Lessons in practical hygiene for use in schools / by Alice Ravenhill ; with preface by M.E. Sadler.

  • Alice Ravenhill
Date:
[1907]
Catalogue details

Licence: In copyright

Credit: Lessons in practical hygiene for use in schools / by Alice Ravenhill ; with preface by M.E. Sadler. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    181/762 page 167
    {B) Coayulation. (1) By heat. [a] Arrange a beaker, three-parts full of cold water, on a retort stand over a Bunsen burner. Take 5 c.c. of undiluted egg albumin in a test tube, and support the tube in the beaker by passing it through the smallest ring of the retort stand, which must be fixed above and just over the centre of the beaker. Introduce a thermometer into the test tube, taking care that the bulb is well covered by the egg albumin solution. Support the thermometer in this position by adjusting a second ring of the retort stand for the purpose, through which the upper part of the thermometer can be passed. Light the Bunsen burner and gradually heat the water, stirring it continually with the test tube. Note what changes take place in the egg albumin, and at what temperature they occur. (i) Drop some egg albumin on the surface of boiling water; compare results Avith those obtained in [a). (c) Repeat but substitute for the egg albumin (1), 6 c.c. of milk and (2), 5 c.c. of juice squeezed from fresh, raw, lean meat. Compare the results obtained in each case with those in [a) and note the tem- perature at which coagulation occurs in each experiment. Note.—To coagulate the albumin in milk by heat, it is nece;sary to heat the milk several times, allowing it to cool in the intervals. (2) By acid. To 5 c.c. of nitric acid in a test tube, add an equal quantity of egg albumin solution, and notice how very rapidly coagulation takes place. The same test for the coagulating power of strong acids upon proteids may be repeated with milk, or with the serum of blood, or with fresh meat juice.
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