Practical physiological chemistry : a book designed for use in courses in practical physiological chemistry in schools of medicine and of science . ne end and the middle finger atthe other. After the two fluids have beenthoroughly mixed the diluting fluid con-tained in the capillary-tube below the bulbshould be discarded in order to insure thecollection of a drop of the thoroughly mixedblood and diluting solution for examina-tion. Transfer a drop from the pipette tothe ruled floor of the counting chamber and,after placing the cover-glass firmly in position,1 allow an 1 If the cover glass is in
Practical physiological chemistry : a book designed for use in courses in practical physiological chemistry in schools of medicine and of science . ne end and the middle finger atthe other. After the two fluids have beenthoroughly mixed the diluting fluid con-tained in the capillary-tube below the bulbshould be discarded in order to insure thecollection of a drop of the thoroughly mixedblood and diluting solution for examina-tion. Transfer a drop from the pipette tothe ruled floor of the counting chamber and,after placing the cover-glass firmly in position,1 allow an 1 If the cover glass is in accurate apposition to the counting cell New-tons rings may be plainly observed. Thoma-Zeiss Cap-illary , Erythrocytom-eter; B, leuco-cytometer. i:i.!>. I83 interval of a few minutes to elapse For the corpuscles to settlebefore making the count. Now place the slide under themicroscope and count the number of erythrocytes in a num-ber of squares, counting- the corpuscles which are in contactwith the upper and the righl hand boundaries of the squareas belonging to that square. Take the squares in some definite Fig. Ordinary Ruling of Thoma-Zeiss Counting Chamber. (Da Costa.) sequence in order that the recounting of the same corpusclesmay be avoided. Of course, all things being equal, thegreater the number of squares examined the more accuratethe count. It is considered essential under all circumstances,where an accurate count is desired, that the counting chambershall be filled at least twice and the individual counts made ineach instance, as indicated above, before the data are deemedsatisfactory. To calculate the number of erythrocytes per cubic milli-meter of undiluted blood proceed as follows: Determine thenumber of corpuscles in any given number of squares anddivide this total by the number of squares, thus obtaining theaverage number of erythrocytes per square. Multiply thisaverage by 4,000 to obtain the number of erythrocytes per i84 PHYSIOLOGICAL CHEMIS
Size: 1597px × 1564px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherphiladelphiablakis
