Volume 1

The principles of pathology / by J. George Adami.

  • Adami, J. George (John George), 1862-1926.
Date:
1909-10
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: The principles of pathology / by J. George Adami. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    IS INTERCELLULAR SUBSTANCE LIVING ? 9]9 (e) Lee itho proteins.—Compounds of the protein molecule with lecithins (lecithans, pliosphatids).1 III. Derived Proteins.—1. Primary Protein Derivatives.—Deriva- tives of the protein molecule apparently formed through hydrolytic changes which involve only slight alterations of the protein molecule. (a) Proteans.—Insoluble products which apparently result from the incipient action of water, very dilute acids or enzymes. (b) Metaproteins.—Products of the further action of acids and alkalies whereby the molecule is so far altered as to form products soluble in very weak acids and alkalies but insoluble in neutral fluids. This group will thus include the familiar “acid proteins” and “alkali proteins,” not the salts of protein with acids. (c) Coagulated Proteins.—Insoluble products which result from (1) the action of heat on their solutions, or (2) the action of alcohols on the protein.2 3 2. Secondary Protein Derivatives?—Products of the further hydro- litic cleavage of the protein molecule. (a) Proteoses.—Soluble in water, uncoagulated by heat, and precipi- tated by saturating their solutions with ammonium sulphate or zinc sulphate.4 (b) Peptones.—Soluble in water, uncoagulated by heat, but not pre- cipitated by saturating their solutions with ammonium sulphate.5 (c) Peptids.—Definitely characterized combinations of two or more amino-acids, the carboxyl group of one being united with the amino group of the other, with the elimination of a molecule of water.6 APPENDIX B. IS INTERCELLULAR SUBSTANCE TO BE REGARDED AS LIVING MATTER? The long-established conception of the constitution of the multicellular organism is that it is of the nature of a community of individual cells 1 Omitted by British committee on the ground that the nature of these bodies is not yet determined, whether true chemical combinations or adsorption compounds. 2 The British Committee object as regards (a) and (c) that they see no object in singling out for special mention a few of the infinite varieties of insoluble modifica- tions which proteins exhibit. 3 The term secondary hydrolytic derivatives is used because the formation of the primary derivatives usually precedes the formation of these secondary derivatives. 4 As thus defined, this term does not strictly cover all the protein derivatives commonly called proteoses, e. g., heteroproteose and dysproteose. 6 In this group the kyrins may be included. For the present we believe that it will be helpful to retain this term as defined, reserving the expression peptid for the simpler compounds of definite structure, such as dipeptids, etc. 6 The peptones are undoubtedly peptids or mixtures of peptids, the latter term being at present used to designate those of definite structure.
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