A study of the blood in rickets

For the purposes of this study I have examined the blood in thirty cases of active, uncomplicated rickets in children between the ages of 13 months and three years. One case of a child aged 6.5 years I have included because I felt justified in classing it as a case of pure active rickets. The majority of these cases were under the care of the physicians to the Northern Hospital, Manchester, to whom I am much indebted for the opportunity of examining them. The remainder came under my observation in the Out- patient Department of the Oldham Infirmary. My examinations were timed so as to exclude all avoidable sources of error. In every case the blood was taken at least three hours after a meal (in order to exclude digestive lymphocytosis), and at about the same time of day. The corpuscle enumeration was made by means of the Thoma -Zeiss apparatus, using a dilution of 1 in 200 and Toisson's solution as a diluting medium. The red cells deposited on one square millimetre - frequently those on two square millimetres - and the white corpuscles distributed over eighteen square millimetres were counted. This operation was made possible by the use of the Elzholz ruling on the Thoma-Zeiss slide, a device which considerably shortens an otherwise lengthy operation. The haemoglobin was estimated with a von Fleischl instrument with which, in my opinion, a greater degree of accuracy is possible than by the use of the instrument of Gowers. In every instance Tallgvist's "Haemoglobin Scale" was used in addition and confirmed the results obtained by the Fleischl apparatus to within 5 per cent. The specific gravity of the blood was estimated by the method of Hammerschlag (chloroform-benzol mixture), and after a little practice with the blood of normal individuals I was able to obtain readings involving a possible error of not more than 1 per cent. At the same time a number of blood films were made on slides, and the best of these were suitably stained and examined under a 1 /12th inch objective. Louis Jenner's stain was found to yield the most uniform results, and in some cases Leishman's modification of Romanowski's stain was used with equally satisfactory results. A differential count was made of 1000 leucocytes, and in the majority of cases the figures were confirmed by a second census. The classification recommended by Ehrlich was adopted. (Under the term 'lymphocyte' I include both small and large lymphocytes, while the term 'large mononuclear' covers "transitional" cells and large "hyaline" mononuclear cells.) The characters of the red corpuscles were noted at the same time as the leucocyte census was made, abnormal forms were counted, and the estimation per cubic millimetre made later.

Grantor dc:publisher

The University of Edinburgh

Year dc:date.issued

1906

Author dc:creator

• Marais, David Pieter

Handle dc:identifier.uri

http://hdl.handle.net/1842/28535

OAI identifier oai:identifier

oai:era.ed.ac.uk:1842/28535