Laboratory studies in tropical medicine / C.W. Daniels and H.B. Newham.

  • Daniels, C. W. (Charles Wilberforce), 1862-1927.
Date:
1911
Catalogue details

Licence: Public Domain Mark

Credit: Laboratory studies in tropical medicine / C.W. Daniels and H.B. Newham. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    56/576 (page 36)
    This is done by placing ;i second metal box (fig. 15, H) on the top of the glass plate. This metal box has a central tube rising bom the bottom and open below, and this tube must be wide enough to enclose the zinc- plate and specimen. If the metal box is also filled with the freezing mixture, the air in the central tube will be cold, and the specimen surrounded by this cold air freezes readily. When the specimen is frozen, the upper metal box can be removed, and sections cut. In this instrument the specimen remains fixed, and the thickness of the section is regulated by alterations in the level of the razor. This is arranged by having the razor blade fixed on a tripod ; the length of the legs of this tripod can be regulated by turning the milled heads of the screws. The feet of the tripod are tipped with bone so as to slide evenly over the glass. For use the blade of the razor must be wetted with water, and the tripod carrying it is so arranged that one leg is anterior. The two posterior screws are turned till the edge of the razor is horizontal or parallel with the sur- face of the glass. Any alteration in the screw of the anterior leg will then raise or lower the edge of the blade. The sections are cut by gliding the tripod over the plate till the edge of the razor touches the specimen, and cuts through it. A slightly oblique motion is the best, and the tripod must be pressed firmly on the glass plate and the movements must be rapid, more like a thrust. The knack of making the correct movement is soon acquired. When a section is cut, the tripod is drawn back, slightly tilting it to avoid touching the specimen, the anterior screw turned to an amount regulated by the thickness of the desired section, and again thrust forward. This process should be repeated until there are several sections on the upper surface of the blade of the razor, and these can be removed with a camel's hair brush to a vessel con- taining water which has been recently boiled, so as to be