Methods of staining the nervous system / by Bernhard Pollack ; translated from the 2nd German ed. by William R. Jack.

  • Pollack, B. (Bernhard)
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: Methods of staining the nervous system / by Bernhard Pollack ; translated from the 2nd German ed. by William R. Jack. Source: Wellcome Collection.

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

    105/164 (page 89)
    As in the re-action occurring in Golgi's method, we find in Ehrlich's that in the most successful preparations only a portion of the nerve- fibres is to be seen, and that they are apparently stained in a quite unselective manner. Even in his first publication, Ehrlich endeavoured to find the explanation, and he finally adopted the view that the re-action of the nervous system to methylene blue depends upon two conditions—saturation with oxygen and an alkaline re-action. It may be pointed out that, as a matter of fact, the cerebral cortex must contain substaAces of an alkaline re-action, for Liebreich and Langgen- dorf found that fresh pieces of the cortex turned litmus blue. But Lieberkiihn and Edinger, using an infusion of alizarin, noticed that the brain became yellow after the introduction of a violet soda compound, and referred this to an acid re-action of the cortex. One must, therefore, admit the existence of substances, some of which have an acid, and some an alkaline re-action. If we further admit the existence of substances with a neutral re-action, we come with Ehrlich to the conception that in the nervous system there are, according to the degree of functional activity, various degrees of ^alkalinity, which, in conjunction with the changes in the amount of oxygen, determine what foreign bodies may be taken up in the special parts of the nervous system. Addendum.—The Treatment op the Retina. It is perhaps of service to insert in this place a section dealing specially with the staining of the retina, an organ in many ways the most marvellous of the entire body. In no part of the central nervous system, perhaps, have so many important researches and discoveries of a general anatomical and physiological nature been made; in no part, perhaps, have the two most important methods, those of Golgi and Ehrlich, within the last ten years proved themselves of such service, as in this, the only free-lying part of the central nervous system, no other part of which is so easily obtained in a fresh condition. It will be understood that I do not make any claim to give in this place a complete description of the methods of dealing with the retina. It is not my intention to do so, nor would it be to the purpose. It would scarcely be possible to do so without going more deeply into the microscopic anatomy of