Abstract: An infinity-corrected, semi-apochromatic microscope objective having an N.A. of 0.95 has five elements and provides a magnification of 100.times. when used with a telescope objective having an effective focal length (efl) of 183 mm.

Abstract: A component microscope objective has a numerical aperture of 0.80. When used with a telescope as described in U.S. Pat. No. 3,355,234, the objective provides a magnification of 63X in an embodiment having a focal length of 2.90 and is well corrected for the usual chromatic image aberrations, spherical aberration, coma and astigmatism.

Abstract: Apparatus for fixation, dessication, and embedding of biologic specimens for microscopic, especially electron microscopic studies having compartment for treating specimens held in liquid permeable specimen holders, a supply of treatment liquid connected to the compartment, to introduce liquid from the supply, and remove liquid from the compartment, a chamber (14c) in the compartment for holding a quantity of fluid, a passage connected to the chamber, pump (15) located in the chamber for moving fluid through the passage, at least one tubular cell (14a) for supporting a plurality of specimen holders (10, 10a) is an end to end relationship, one end of said cell being connected to said passage, the other end of each of said chamber and said cell being connected to a common portion of said tank to permit liquid to be circulated by said pump.

Abstract: The invention concerns a device for the cryo-substitution of small biological objects for microscopic, especially electron microscopic investigations, with a metal receptacle for the reception of at least one object, which is mounted in a dewar flask containing a liquid cryogen and which can be regulated to a desired temperature by means of the cryogen and a regulatable heating device joined to the receptacle.

Abstract: The invention concerns a device for metallic mirror-cryofixation and subsequent cryopreparation of biological materials for microscopic, in particular electron microscopic examinations, employing a highly polished metallic mirror cooled to very low temperatures by a cryogen and mounted in a metal freezing chamber, which can be flooded with a gaseous cryogen, on which an object can be placed by means of an injection mechanism or the like, wherein the freezing chamber has an adequate volume for cryopreparation and for accepting the required accessory devices.

Abstract: A specimen working chamber having heat-conductive walls instead of insulative walls is disclosed.

Abstract: A tray for holding a biological specimen and a submersible container for freeze-drying the specimen are disclosed. A heating element to melt a synthetic resin for embedding the specimen is also disclosed.

Abstract: A joint having a plurality of spherical elements cemented to one member and the other member having adjustable sockets which cooperate with the spherical elements to permit rotation about a single axis. The joint is particularly useful in microtomes and ultramicrotomes.

Abstract: A positive and negative lens of equal power can provide the means to scan small objects being observed through a microscope if one of the lenses can be selectively decentered. The arrangement is particularly useful for microscopes having photometers that are used to analyze very small specimens, such as chromosomes, by scanning.

Abstract: An interference filter having a plurality of alternating layers of high and low index of refraction and layer thickness increasing toward the center can compensate for errors in spectral energy distribution produced by an optical system.

Abstract: An adjustable filter regulator for a microspectrophotometer including adjustment means connected to a scale for controlling the setting of the interference filter wherein the filter is moveably connected to a servomotor; follower circuit, differential amplifier, and signal transmitter.

Abstract: An alternating light photometer, the output of which is connected over two parallel uniform current paths with both of the inputs to a differential amplifier. In each of the paths, there is included in series a resistance, a condenser, with a switch provided as well as between a switch and corresponding input of the differential amplifier, and an operational amplifier, all forming a storage circuit. The R C circuit forms a low pass with a time constant over the given engaging or disengaging time of the beam. The switches are so controlled over the switching circuit that only one of them is closed during the time of the complete release, and the other only during the time of the complete interruption of the beam to the photoelectric transducer.

Abstract: A method and apparatus for transferring frozen sections from a microtome or ultramicrotome to a microscope or the like without the deleterious effects of the ambient conditions. The apparatus includes a temperature regulated cooling means and protective enclosure to protect the frozen specimen during the transfer. The apparatus can be plugged into the vacuum chamber of an electron microscope and then the protective enclosure removed to present the frozen specimen for examination.

Abstract: By using two or more masks in a microscope having an optical system with an intermediate image plane therein in combination with a camera, composite photomicrographs can be prepared with two or more images.