The elements of pathological histology with special reference to practical methods / by Anton Weichselbaum ; tr. by W.R. Dawson.

  • Weichselbaum, A. (Anton), 1845-1920.
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: The elements of pathological histology with special reference to practical methods / by Anton Weichselbaum ; tr. by W.R. Dawson. 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.

    49/530 page 23
    For purely histological investigations, homogeneous immersion [oil-immersion] systems of lenses are not indispensable, although absolutely so for examining bacteriological preparations. If the latter are stained, Abbe's illuminating apparatus must also be em- ployed, which indeed may render very good service with stained histological preparations also.^ The most recently introduced systems of lenses, the so-called cfpo- chromatic objectives, considerably surpass those hitherto employed in excellence; but they do so in price also, and can, moreover, be per- fectly well dispensed with in purely histological research. It is only in bacteriological investigation, and in micro-photography, that their peculiar value comes to the front; and the same also applies to the compensation and projection eye-pieces used in connection with them. A microscope should be obtained only from a well-known firm, such as, foremost of all, that of Zeiss in Jena, and then, in alpha- betical order, those of Hartnack in Potsdam, Leitz in Wetzlar, Reichert in Vienna, and Seibert in Wetzlar. [In England the firms of R & J. Beck and of J. Swift & Son may be mentioned as making excellent instruments. The lenses of Powell & Lealand also have an unsurpassed reputation, but their prices are extremely high.] The following combination from Eeichert's establishment can be recommended for ordinary histological investigation :—Stand l^o. III. (with nose-piece for two objectives), dry objectives Nos. 3 and 7a, and eye-pieces III. and IV., magnifying from 80 to 440 times; price, £7 lis. For bacteriological research the Abbe's apparatus and the homogeneous immersion lens 185 (magnifying 950 times) must further be added, which would raise the total price to £14 Is. If a larger stage ^ be wished for, which can be made to revolve, stand No. II. & should be chosen, and the homogeneous immersion 19& or 18a is also preferable to that before mentioned. If, further, an iris diaphragm is desired, and three dry objectives instead of two—say, Nos. 3, 6, and 8a, with nose-piece—and a micrometer eye-piece in addition to the other two,^ the total price rises to £24 16s. or £26 6s. respectively. ^ All requisite information regarding the use of immersion systems and of tlie ilUmiiiiating apparatus will be found given in the catalogues of the different firms of opticians. Cedar oil is removed from cover-glasses with benzol or xylol, but it is not advisable to do this until the balsam used in mounting has become hard. ^ Desirable for examining culture plates. ^ The approximate value of the graduated intervals in the micrometer eye-piece can be made out from the table usually given with the microscope ; the exact value of the intervals for the combinations of objectives and eye-pieces used could only be ascertained by means of a stage micrometer^ the latter being used as an object.
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