Manual of chemical physiology / from the German of C.G. Lehmann ; translated with notes and additions by J. Cheston Morris ; with an introductory essay on vital force by Samuel Jackson.

  • Lehmann, Karl Gotthelf, 1812-1863.
Date:
1856
Catalogue details

Licence: Public Domain Mark

Credit: Manual of chemical physiology / from the German of C.G. Lehmann ; translated with notes and additions by J. Cheston Morris ; with an introductory essay on vital force by Samuel Jackson. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    HISTOCHEMISTRY. SCIENCE OF THE ANIMAL TISSUES. The chemical investigation of the animal tissues presents in many- respects still more difficulties than that of the animal fluids. These lie partly in the fact that most of the tissues are very intimate commin- giings of different substrata which cannot be separated from each other mechanically; and partly, that all tissues are alike insoluble in the ordinary indifferent menstrua, and undergo such important mo- difications by the more active solvents, that their original constitution can hardly be guessed at. Hence, but little progress has been made in the knowledge of even the simpler animal tissues. The only method which can lead to a more exact acquaintance of the consti- tutions of tissues, and has already so done in part, is to cause the operation of different chemical reagents upon the simple tissues under the microscope, in order to ascertain the chemically homo- geneous tissue-elements. Microchemistry has already rendered im- portant services to Histology, as the true composition of certain tissues (e. g. horn, &c.) was first recognized by means of it. In physiological chemistry it affords us in a measure the key with which to open the approach to a rational investigation of the com- position of animal tissue; for while it allows us to separate the chemically homogeneous from the chemically different, it often gives us the means to institute a chemical separation on a large scale, and thus subject the individual elements of tissue to a pure chemical investigation. Macrochemical analysis must follow the microchemical. Although histochemical investigations hitherto have not led to many general propositions and theories, a proposi- tion has been established that the chemical nature of the tissue or of the important tissue elements always corresponds with their func- tion. Although we know not yet what causes render this or that