Investigations on microscopic foams and on protoplasm : Experiments & observations directed towards a solution of the question of the physical conditions of the phenomena of life / By O. Bütschli ... Authorized translation by E. A. Minchin.

  • Butschli, O. (Otto), 1848-1920.
Date:
1894
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Licence: Public Domain Mark

Credit: Investigations on microscopic foams and on protoplasm : Experiments & observations directed towards a solution of the question of the physical conditions of the phenomena of life / By O. Bütschli ... Authorized translation by E. A. Minchin. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    EXPLANATION OF THE FIGUEES 1 Since I have prepared the figures for the most part without the aid of the camera, under the erroneous impression, as was afterwards found, that by its help delicate protoplasmic structures could not be recognised with certainty, I often have no sure means of determining the magni- fication in cases where direct measiirements were not taken. In general, however, the figures relating to protoplasmic structures are drawn with a magnification of about 2500 to 3500 diameters, as is proved by those in which the magnification was actually determined. As I have said, I convinced myself at a later period that, in preparations of sufficient clearness, the protoplasmic structures can be drawn quite well by the help of the camera, using Zeiss's 2 mm. and Oc. 18 ; to which fact Fig. 2 on Plate X. bears witness, for example. Since the size of the alveoli varies within relatively narrow limits, that is to say, between 0-5 to 1 /x., the magnifications can be determined fairly well from this fact. Whenever it is not stated otherwise, the figures are all done with Zeiss's Apochr. 2 mm., Ap. P30 or P40, and the Comp. Oculars 12 or 18. 1 An Atlas of 19 Microphotographs in connection with this Work can be obtained from Professor Biitschli, Zoologisches Institut, Heidelberg, by send- ing the sum of five shillings.