Two monographs on malaria and the parasites of malarial fevers / I. Marchiafava and Bignami, II. Mannaberg.

  • New Sydenham Society
Date:
1894
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Licence: Public Domain Mark

Credit: Two monographs on malaria and the parasites of malarial fevers / I. Marchiafava and Bignami, II. Mannaberg. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    treatment by picric acid. Specimens prepared in the method which has been described show the parasites, as also the leuco- cytes, coloured blue ; the red blood-corpuscles remain perfectly colourless. In successful preparations the details of the structure of the pai'asites are very clearly shown (see Plate III). For stainiug blood parasites in tissues, Bignami Amico [50] gives the following directions : Fix the finely cut sections of tissue in a i per cent, watery solu- tion of corrosive sublimate with 075 per cent. NaCl and o5 to i per cent, acetic acid. The sections remain in this solution from half an hour to several hours; they are then hardened, first in iodised alcohol, lastly in absolute alcohol. Staining follows in saturated watery or alcoholic solutions of safranin, methylene blue, vesuvin, or magenta-red for five minutes, subsequently washing in alcohol. Apart from the staining methods, there are further various attempts suggested with the object of retaining the haematozoa alive as long as possible, in order to observe any possible developmental appearances or modes of reproduction. To attain this object it is necessary to prevent the coagulation of the blood, to avoid evaporation, and to keep the specimen at a constant temperature. To prevent coagulation, Plehn [28] recom- mends the adoption of Freund^s [59] method. The tip of the finger, from which the blood is to be taken, is well smeared with vaseline, and then an ordinary microscope slide must be used, which by means of a flat ring of a spirit varnish has been converted into a hollow slide; a drop of fluid paraffin should also be placed upon the cover-slip, so that the blood is prevented from touching any sub- stance which would favour coagulation. Plehn states that with such precautions the blood-corpuscles retain for two or three days their normal shape and their elasticity. To prevent evaporation, Hayem's slides (cellule a rigole), already mentioned, are used, or the edge of the cover-slip is ringed with paraffin ; the hollow microscope slide, into which a small drop of water has been placed, is also useful for this purpose. I often use with considerable success a hollow microscope slide which is at one and the same time a moist and oxygen chamber. It consists of a rather thick glass, having in the middle a deep depression, as is the case in the ordinary hollow slides. Into this depression two grooves are ground, into each of which a thin ebonite tube is cemented, projecting about 3 or 4 cm. beyond the end of the slide. The cementing must be very accurate, 17