The blood, how to examine and diagnose its diseases.

  • Coles, Alfred Charles.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: The blood, how to examine and diagnose its diseases. 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.

    40/318 (page 24)
    According to Hayem, when films have been prepared for a month or more the haemoglobin adheres more firmly to the corpuscles than at the time of preparation. For practical purposes it is necessary to use one of the following methods in order to fix the haemoglobin of the red cells of the film. By weans of Heat.—Ehrlich, to whom we are in- debted for the film method of examination of blood, subjected the air-dried preparation, placed on a copper plate, to a temperature of iio°-i20° C. for two hours or more. Lowit placed the films — which had first been allowed to dry very thoroughly in the air—in an oven at a temperature of iio°-ii5° C. for one to two hours, allowing a gradual increase and decrease in the heat. He pointed out that too great heat, or heat extending over too long a time, destroys the structure of the nuclei. This method of treatment takes too much time for clinical purposes, and many of the recent observers ao-ree that much of the finer detail of structure is altered by it. No doubt passing the coverglass film two or three times through the flame of a spirit lamp or bunsen burner, as commonly advised, answers the purpose fairly well. After trying the latter method of heating for some years I found that for certain stains, particularly Ehrlich's acid haematoxylin solution, very thorough fixation was necessary; and moderate application of heat was usually followed by disintegration or total disappear- ance of the film when treated with such stains as the above, whilst too great heat spoils some of the nuclear structure.