Physiological histology, methods and theory / by Gustav Mann.

  • Gustav Mann
Date:
1902
Catalogue details

Licence: Public Domain Mark

Credit: Physiological histology, methods and theory / by Gustav Mann. Source: Wellcome Collection.

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    Unna (1894), who has done so much for the minute investigation of the skin, worked out an elaborate system of specific stainsx, which led him to the following conclusion: Flemming’s and Biitschli’s views are not necessarily opposed to one another ; for a cell, according to its state of health, may either show a filar or a foam-like proto¬ plasm, and fibrils may even run along and through the foam-like remainder of the protoplasm2. In 1894 Alfred Fischer 3 commenced his researches, which he has continued up till now. He originally took up his investigations in order to determine whether the granules which Altmann obtained with his fixative were artefacts. Subsequently he extended his researches to all classes of chemically pure proteids3(b It is Fischer’s chief merit to have shown that from an intimate ‘ homogeneous ’ mixture of albumose and albumin, the former may be precipitated in a granular form by certain reagents, including Altmann’s mixture, while the albumin is thrown down as a net-like coagulum. Hardy, in 1899, attacked the microscopical appearances from a physical point of view, in a similar manner to that of Btitschli and Quincke. His results may be briefly summarized thus: Coagulation, whether it take place spontaneously at death, or whether it be induced by fixatives in living cells or colloidal structureless substances such as filtered white of egg or gelatin, is always accompanied by the separa¬ tion of a fluid part from a solid net-like structure, ( which differs in most cases in kind, in some cases in degree, from the initial structure.’ During the two years 1888-9 I4 continued the work of Flemming, Berthold, and Schwarz, and made a systematic study of the various reagents used by physiological chemists for precipitating proteids. The material experimented on was Spirogyra nitida, the hairs of Tradescantia during rest and division, the growing apices of leaves of liliaceous plants, and white of egg. I confirmed the observations of Schwarz regarding the effects produced on white of egg by the fixatives he employed, but I did not attribute much importance to them, because I considered egg-white to be a dead substance which need not behave at all like a living cell. Living tissues, whilst under microscopic observation, were subjected to the action of a number of fixatives in dilute and concentrated watery and alcoholic solutions. As the result of two years’ work I came to the conclusion that saturated alcoholic and watery solutions of picric acid in combination with corrosive sublimate and tannin were the most vigorous precipitating agents, and that for this reason they ought to be employed. With saturated solutions of picric acid and sublimate in absolute alcohol more homogeneous precipitates were obtained Unna, ‘ fiber Protoplasma-Farbung nebst Bemerk. ii. d. Bindegewebsz. d. Cutis,’ Monatsschr. f. prakt. Dermat. 19, 22641894). ,, ^nna? ^ber L neueren Protoplasmatheorien u. d. Spongioplasma/ Deutsche Med izmalzeitung (1895'. 4 Fischer, (a) ‘ Zur Kritik d. Fixirungsmethoden/ Anat. Am. 9 (1894). (.?) •Weue z* Kritik d. Fixirungsmethoden,’ Anat. Am. 10 (1895). (c) Uber cL Bau- d- Cyanophyceen u. Bakterien, Jena, 1897. A) Fixirung, Fdrbung u. Bau d. Protoplasmas, Jena, 1899. Mann, Trans. andProc. Bot. Soc., Edinburgh, 18th session 1889-90, pp. 429, 443.
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