Practical histology and pathology / by Heneage Gibbes.

  • Gibbes, Heneage, -1912.
Date:
1880
Catalogue details

Licence: Public Domain Mark

Credit: Practical histology and pathology / by Heneage Gibbes. Source: Wellcome Collection.

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    and he should see that they are tested on some histo- logical object, and not on diatoms, as the wide angle necessary for resolving test diatomacese are the reverse of useful to the young Histologist. The most important glass for the student is the high power, and it is neces- sary that this should be a good one. High Poivers. The best high powers are made by Messrs. Powell and Lealand, they are of course expen- sive but pay well in the end; they are made with correction collars and are more adapted to large stands with mechanical stage. Zeiss’ E = J and F = ^ are very good glasses, and well adapted to the students’ stand and are not expensive; they have no correction collar, and the cover glasses should be measured to get the best effect; *006 will do very well for D and E, and •004 for F, the same applies to Mr. Crouch’s ^ which is corrected to a cover glass of *006. Oil Immersion Lenses. These glasses are taking the place of water immersion high powers in Histologi- cal research, as they have no correction for thickness of cover glass, and are consequently much easier to use, the only drawback is that the essential oil used will dissolve Canada balsam, Dammar varnish, and many of the other sealing fluids, and it is necessary to cover them with Plollis’ glue which is not acted on by cedar oil. These glasses were first made by Zeiss of Jena, and since by Messrs. Powell and Lealand. The first glass made by Zeiss was the ■§-, he then brought out a T^- and afterwards a ^g-, of these the is unquestionably the best glass. Messrs. Powell and Lealand have made tuj tV> an^ A 011 this principle, and have succeeded in removing a great objection to oil immersion lenses;