Practical pathology : a manual of autopsy and laboratory technique for students and physicians / by Alfred Scott Warthin.

  • Aldred Scott Warthin
Date:
1911 [©1897]
Catalogue details

Licence: Public Domain Mark

Credit: Practical pathology : a manual of autopsy and laboratory technique for students and physicians / by Alfred Scott Warthin. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

    329/354 (page 305)
    MICROSCOPIC EXAMINATIONS FOR MEDICO- LEGAL PURPOSES. 1. BLOOD. Fresh spots should be scraped off and examined in physiologic salt solution. Older spots are scraped off when pos- sible, or if the spots are on clothing or other fabrics, a piece of the stained portion is cut out, and the scraping' or piece of material is placed on a slide in a macerating fluid (30 per cent caustic potash; glycerin 3 parts and concentrated sulphuric acid 1 part; 15 per cent tartaric acid; equal parts alcohol and ether; or Pacini's fluid [mer- curic chloride 1 grm., sodium chloride 2.0 grm., glycerin 100 cc, water 300 cc.]). Even in very old clots or stains some red cells may retain their characteristic form. The process of maceration should be observed directly under the microscope, as the macer- ating fluid gradually changes the cells after they become loosened. Schmorl advises the following method:-—■ Moisten a small piece of the fabric in water and stain with hsematoxylin. Differentiate in acid alcohol, wash thoroughly in water, stain with 1/1000 watery eosin solution, wash in water (3-6 hours), place in alcohol, and then again in water. Tease with great care into fine threads on the slide, and examine the isolated fibres in a drop of glycerin. The red corpuscles are easily recognized; and the nuclei of the white cells or of the red cells of birds and amphibia stand out distinctly. Permanent mounts may be made by passing the specimen through alcohol, xylol, and mounting in balsam. A portion of the stained fabric may be imbedded in celloidin, sections cut, and stained with hematoxylin and eosin. The red cells may be measured by the ocular micrometer. Those of man are somewhat larger than those of other mammals, but the difference in size is so slight that an absolute determination of the source of the blood is not possible from the consideration of size alone. Human corpuscles measure 0.0077 mm. in diameter; the nearest in size are the corpuscles of the dog, rabbit, hog, cow, horse, cat and sheep, in the order given, those of the sheep being smaller. The measurements of a large number of corpuscles must be taken if the question of size is to be considered. When red cells cannot be found the stains must be tested for the presence of blood