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.

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    carrier and applying the paraffin block firmly to it, and keeping it in position till the carrier is cold. (3) That the thickness of section must be graduated in accordance with the nature of the tissue, its brittle- ness, and object of the section. If the specimen is too hard or brittle it is useless to expect thin sections. Sections showing large parasites, such as filaria, in tissues like the lung, should not be too thin. For the details of nerve structure, and for sections showing bacilli, or the parasites of malaria, the thinnest possible sections are the best. Celloidix Sections.—For cutting celloidin sections a slide microtome, such as that of Jung, is best, but quite good sections may be obtained with the Cambridge Rocker. A form of this instrument should be selected in which the razor can be placed obliquely. These sections are generally cut in alcohol. The sur- faces of the celloidin block and of the knife should be moistened with alcohol by means of a camel's hair brush. Place the knife so that it forms a slight angle with the block. Transfer the cut section to 70 per cent, alcohol with a brush or with the finger. From paraffin blocks sections 5 to 7 //, in thickness may be obtained ; from celloidin blocks sections 10 to 15 /x are generally cut. Fixation of Paraffin Sections on Slide.—For ordinary work the sections, when cut, are placed on the surface of some warm water at about 440 C, or rather more if paraffin of a higher melting point is used, in order to straighten them out, and can then be floated on to a slide. The water is allowed to drain off, and the slide is then placed in the hot incubator for twelve to fifteen hours. The section will then be fixed to the slide. Occasionally it will be found that the sections after removal of the paraffin fall off. In such a case the other sections may be very gently warmed over a flame till the paraffin begins to appear more translucent and then allowed to cool.