A manual of clinical diagnosis by means of microscopic and chemical methods : for students, hospital physicians, and practitioners / by Charles E. Simon.

  • Simon, Charles E. (Charles Edmund), 1866-1927.
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: A manual of clinical diagnosis by means of microscopic and chemical methods : for students, hospital physicians, and practitioners / by Charles E. Simon. Source: Wellcome Collection.

    83/620 (page 71)
    The Plaques. In addition to the leucocytes and erythrocytes large numbers of small, roundish elements are encountered in the blood, which are free from coloring-matter and may be frequently observed collected into small heaps, resembling bunches of grapes. These are the blood-plates or plaques of Bizzozero. According to Hayem, they represent ordinary red corpuscles in an early stage of development, and have hence been termed hcematoblasts. This opinion, however, is not shared by many hasmatologists. According to Osier, they number from 200,000 to 500,000 per cbmm. under normal conditions, and are said by Hayem to occur in greatly diminished numbers in the blood in pernicious antemia. ' This observation, however, lacks confirmation. In order to demon- strate their presence the drop of blood should at once be mixed with Hayem's fluid (see p. 72). The Enumeration of the Corpuscles of the Blood by the Method of Thoma-Zeiss. Of the various instruments employed for the enumeration of blood-corpuscles, that of Thoma-Zeiss appears to be the most satis- factory. (Fig. 16.) Fig. 16. Thoma-Zeiss blood-counting apparatus. It consists of a capillary pipette (S) having a bulb in its upper third, the lower end being graduated in parts numbered from 0.1 to 1, while above the bulb a mark bearing the number 101 is