75 
Haemacytometer after Thoma. TIus apparatus consists 
of 1) a cross-line micrometer, being a sq. mm divided into 40() 
squares, which forms the bottom of a cell having an exact depth 
of 0.1 mm, and 2) a blood-mixing pipette (melangeur), which is 
also, of necessity, very accurately calibrated. With instructions. 
In case. 
a) With mixing pipette for red corpuscles 
b) With mixing pipette for white corpuscles 
c) The same apparatus with both pipettes 
Pipettes alone. 
One for red corpuscles (diluting 1 : 100) 
One for white „ ( „ 1 : 10) 
The same apparatus, as Nos. 34*^ <=, with small movable 
stage, to assist the process of counting under the microscope 
M. 10. — extra. 
C. Measuring Apparatus for various 
other purposes. 
Brass Measure, lOO-mm, with chamfered edge .... 
Measures on plate-glass, for drawings, in which the di- 
visions lie on the surface of the paper without parallaxis, with 
fine, sharply engraved lines: 
300 mm glass rule, divided in Vi 
200 mm do. do. 
100 mm do. do. 
50 mm divided in V2 iii^i on a 3X1 inch slip . . . . 
Any other scales to order. 
