On the nature of the substance found in the amyloid degeneration of various organs of the human body / by Francis Harris.
- Harris, Francis
- Date:
- 1860
Licence: Public Domain Mark
Credit: On the nature of the substance found in the amyloid degeneration of various organs of the human body / by Francis Harris. Source: Wellcome Collection.
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![In 1854 he first shewed that certain of the round concentric bodies found in the so-called lining membrane of the ventricles of the brain (ependyma ventriculorum) exhibit a pale blue colour on the addition of iodine, and on the further addition of sulphuric acid, a beautiful violet. This reaction separated these from certain other forms of concentric granules (Brain-sand), and to the class thus distinguished he restricted the name “ Corpora Amylacea.” He considered that this reaction alone was suffi¬ cient to indicate their cellulose nature ; for though he was unable to isolate them in sufficient quantity to subject them to chemical analysis, he considered their cellulose nature beyond doubt, as there was no other known substance in the whole range of animal tissues which produced similar reactions. These observations of Virchow s were repeated by Mr. Busk*, who, however, arrived at the conclusion that these bodies were not cellulose but genuine starch, since they “ possessed all the, “ structural, chemical, and optical properties of starch as it “ occurs in plants.” They exhibited concentric markings,— they coloured blue with iodine,—they acted upon polarized light in the same manner as starch does. Other observers, however, have not been able to convince themselves of the actual starch- nature of these bodies f. Schmidt while distinctly expressing his opinion that the covering of the tunicata is actual cellulose, still thought that the cellulose nature of the corpora amylacea had not at that time been determined. Until, then, these bodies have been shewn to be convertible into sugar, some doubt must exist as to their nature. The occurrence of starch itself, as starch in the human body, has been maintained by Mr. Carter];. In endeavouring to make out the structure of a tumor of the optic nerve, he found a large number of bodies (corresponding to the corpora amylacea of Virchow), which, when brought into contact with iodine, passed through various shades of purple to the densest black. He afterwards examined a long series of tissues, some healthy, others variously diseased, both in the human subject, and in the * Quarterly Journal of Microscopical Science, Vol. II. p. 105. 1853. + Thier-Chemie, p. 255. J Edinburgh Medical Journal, Vol. I. p. 133. 1855. And Ibid, March 1858.](https://iiif.wellcomecollection.org/image/b30564517_0008.jp2/full/800%2C/0/default.jpg)
